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Physics/Questions Answered by Expert Steve Nelson

SubjectDate Asked
Rail gun mania2/9/2012
  Q: I am seeing a lot of ink on science/technology websites lately about rail guns,and how great they ...
  A: Much more than twice, actually, and rail guns are reeeally old-hat. They were invented in 1918, ...
Astronomy2/7/2012
  Q: I am going into 7th grade and want a science fair project about astronomy that would woo the ...
  A: What about astronomy interests you? What kind of equipment do you have? Astronomy projects that ...
hockey pucks2/7/2012
  Q: If two hockey pucks are pushed at the same time from the same straight hockey stick, one puck is 4oz ...
  A: Of course it takes more force to accelerate the larger pucks. In the real world, ice is a funny ...
Balancing of static motorcycle2/6/2012
  Q: It is very difficult to balance a two wheeler when it is non moving unless the leg support is given. ...
  A: Of course it depends on the angle and the location of the center of mas of the motorcycle. You ...
thermodynamic2/6/2012
  Q: what is the thermodynamic assumption made incase of inlet and outlet velocity of the turbine.
  A: Not being a turbine expert, per se, I would have to know more about the turbine. In the case of a ...
Electric Field Lines2/3/2012
  Q: I took a test, and there was a question which is still bothering me, and I'm anxious to see if I put ...
  A: I'm not going to go into specifics, because this really reads like a homework problem, but the ...
seniors thesis1/31/2012
  Q: my seniors thesis (philosophy) was an attempt at outlining an ontological sub-structure of the ...
  A: I can see why they rejected it, for one it's not written in the form of any reasonable journal ...
effect of moon's gravitational pull on cerebral fluid1/30/2012
  Q: When I lie on my back face up, I cannot fall asleep because my brain won't shut off. I keep thinking ...
  A: Not by physics, no, this is a biology issue. And it's not the Moon's gravitational pull (yes Moon ...
general relativity1/30/2012
  Q: Does each and every object even a dust mite bend space time? ANSWER: Yes. This site won't let me ...
  A: What you're poking at is the borderline between relativity and quantum mechanics. No one has been ...
relative strength of forces.1/29/2012
  Q: Steve, I heard a number of times that the force of gravity is considered to be massively weaker than ...
  A: Well, you have the terminoligy slightly wrong. The force it would exert on another body would ...
speed of light1/28/2012
  Q: I asked this question to Richard J. Raridon He replied it was not his expertise I hope it is in ...
  A: What do you mean, light with mass? You mean the light source has mass? Because then you have an ...
relative strength of forces.1/28/2012
  Q: Steve, I heard a number of times that the force of gravity is considered to be massively weaker than ...
  A: Not at all, the strength of the electromagnetic force and the existence of opposite charges is what ...
relative strength of forces.1/28/2012
  Q: Steve, I heard a number of times that the force of gravity is considered to be massively weaker than ...
  A: With your example, you're dealing with a magnetic dipole (north and south ends). With gravity ...
Investigating Static Electricity Using an Electroscope -- fun stuff.1/27/2012
  Q: We performed a lab where using a neutral electroscope, we rubbed a PVC rod with fur, which made the ...
  A: Like charges repel, whether positive or negative. Electroscopes are generally based on ...
Snowboard Physics1/23/2012
  Q: i am conducting an experiment in my science class and was wondering if you would be willing to be my ...
  A: Hey, I'm a snowboarder myself! Amount matters less than texture. The amount matters for how long ...
The Universe1/19/2012
  Q: We know that the Universe is Infinite and expands macroscopically (from the outside). But is true ...
  A: As far as we know, the space in the universe itself is not only expanding but accelerating. I'm not ...
physics1/16/2012
  Q: sir does angle of incidence is equal in irregular reflection to angle of reflection? ANSWER: What ...
  A: No, irregular reflection definitely means that the angle of incidence is probably not equal to the ...
What may be the sources of error in this lab? (Fluid Mechanics)1/13/2012
  Q: We did a Fluids lab, and its procedure is below: Place a bottle with a sealed hole in the middle on ...
  A: While this come reeeeally close to my no-homework policy, you're asking for something much more ...
superconductivity question1/11/2012
  Q: 'Current in a superconductor is not driven by an electric field but but it exists by it self wrapped ...
  A: No, that's not how they work. Electrons have a charge. As such, they distort the crystal lattice ...
Imploding Pop Can1/10/2012
  Q: I am trying to help my son understand a demonstration he saw in school - pop can with a bit of water ...
  A: The question here is whether or not the turning upside-down was the way the can was sealed. If it ...
science fair project-help1/9/2012
  Q: This is my first time on here, and was wondering where a good place to start research would be. My ...
  A: I always liked this one: get a balloon and fill it with like a teaspoon of water, then blow it up ...
Perfect vacuum1/7/2012
  Q: I guess I sort of have two questions, but they're very closely related: How have physicists learned ...
  A: Precision measurement for the first one. The second one is not only the consequence of the form of ...
vacuums and bubbles1/5/2012
  Q: I've found by reading online that a vacuum can hold to a maximum height of roughly 30 feet. ...
  A: Yes, it's impossible, That's basic physics. The reason you mentioned is the why, it would take you ...
How much liquid nitrogen?12/30/2011
  Q: Greetings Steve, A liquid nitrogen evaporation question for you :) This is not homework!! A large ...
  A: This question contains nowhere near the information needed to answer it. How long is the tube, and ...
gravity12/20/2011
  Q: Steve, Does a miner weigh less deeper underground? If I could tunnel to the center of the earth, ...
  A: You need to google something called geodesy, if you're concerned about such small distances relative ...
gravity12/19/2011
  Q: Steve, Does a miner weigh less deeper underground? If I could tunnel to the center of the earth, ...
  A: It would be linear, yes. The miner at the bottom would, of course weight less. I mean, if you ...
Nuclear Energy12/18/2011
  Q: Why don't some countries reprocess spent uranium into plutonium or what are the disadvantages?
  A: There's no logical reason, it's purely political leftover from the cold war. We recycle glass, ...
physics12/12/2011
  Q: If I drop a ball from 3 feet high off the ground who will catch it faster a young or older person ?
  A: That depends. If they catch it at the same height, then they would catch it at the same time from ...
radiation12/9/2011
  Q: is it true that the color blue absorbs radiation
  A: No, it is not. Blue is a color because whatever is colored blue is reflecting blue light and not ...
space12/5/2011
  Q: Is there an accepted theory among scientists of just what space is? Is it like a container within ...
  A: There are many possible theories between scientists about "what space is." But I don't think any of ...
Einstein12/5/2011
  Q: Did Einstein visualize spacetime or was his conception of spacetime purely mathamatical
  A: How do I know what he visualized or didn't? I'm not a time-traveling mind reader. Visualization ...
electromagnetism12/4/2011
  Q: Hey!I was practicing some random questions when i came across one I've never heard anything ...
  A: Well that's definitely not enough to go on to calculate anything. Are you talking about a pinched ...
Candle, mirrors12/2/2011
  Q: If I have a candle in a closed room, I see, of course, one candle. If I add a mirror, I see two ...
  A: You can increase it to a point, but it can only bounce back and forth between mirrors so many times ...
How "mass" works12/2/2011
  Q: I keep reading that we are learning more and more about what "mass," or as I call it 'weight' might ...
  A: If you call it "weight" then you misunderstand the difference between the two. What causes mass to ...
speed and deceleration12/2/2011
  Q: How can I calculate the speed of a vehicle at a given point in its deceleration. Example if a car ...
  A: Well, this is starting to sound like a homework question, but I can tell you that your first formula ...
speed and deceleration12/1/2011
  Q: How can I calculate the speed of a vehicle at a given point in its deceleration. Example if a car ...
  A: Well, you don't have enough information to solve this particular problem. You don't know the ...
speed of light/light photons11/29/2011
  Q: why is the speed of light inviolable? is it just the nature of light to be this speed or do other ...
  A: The speed of light is a result of a wave equation, Maxwell's equations (which collectively form a ...
hypothetical physics11/29/2011
  Q: If one were to implode a small piece of matter into infinite density with extremely high explosive ...
  A: You said infinite, which means it can't be done. And no, if you're referring to things like the ...
relativity11/29/2011
  Q: Dr Mr. Nelson I am taking the liberty of asking a simplistic and maybe silly question. Thank you ...
  A: Let me stop you right there at the words "add on" speed, since that Light travels at the speed of ...
FTL studies11/27/2011
  Q: I recently read in the media about 2 scientific studies which claimed to have discovered particles ...
  A: No, Einstein was a fantastically capable theoretical physicist and mathematical genius. I would ...
Complex 4 Wheeler Automobile Design Model11/27/2011
  Q: This is regarding a Complex 4 Wheeler Automobile Design Model VIZ Cars, Jeeps, Lorries, Bus, Tempo ...
  A: Being a physicist and not an automotive engineer, this is definitely outside of my area of ...
physics11/24/2011
  Q: sir if earth get stopped suddenly to rotate than what happens and sir what will be the effect on our ...
  A: Everything would CRASH! We're traveling at massive velocities! The value of g would increase ...
physics11/23/2011
  Q: What does the "observable universe" encompass. Does it refer to only those things that can be be ...
  A: Observable, as a descriptor, means something we can measure. Neutrinos interact with matter rarely, ...
physics11/23/2011
  Q: sir what will be the time period of simple pendulum having lenth infinity? and how please explain ...
  A: It would be infinite, but or course you cannot create a pendulum of simple gravity in such length. ...
Archery Variation Sport (angular Velocity)11/21/2011
  Q: Do you feel this variation of Archery game can be introduced as a Good Olympics Sport in future ? ...
  A: No, wow, global sports would take a visit to campus and a small set of lectures to make it even ...
Boomerang - Laws of Physics11/21/2011
  Q: http://en.wikipedia.org/wiki/Boomerang How does a Boomerang and Returning Boomerang works ? What ...
  A: It's mostly making sure that the materials are light and then the second part is the geometrical ...
science11/21/2011
  Q: If the law of conservation of matter states that no matter can be destroyed or made then i was ...
  A: Ummm...brain cells "die" means that they are cleaned out by the immune system. It's not physics, ...
massless particles11/20/2011
  Q: the concept of massless particles escapes me. Is a massless particle no more than a theoretical ...
  A: Your problem is not the problem with massless (meaning it can have energy, like a photon, but no ...
Archery and Shooting Games.11/20/2011
  Q: http://en.wikipedia.org/wiki/Archery http://en.wikipedia.org/wiki/Archery_at_the_Summer_Olympics ...
  A: Of course they involve laws of physics, laws of physics govern how everything in the universe moves. ...
What is the statistical chance that there are not a god or creator?11/20/2011
  Q: What is the statistical chance that there are not a god or creator?
  A: The problem is that you've asked a question about the supernatural (i.e. a creator for the universe ...
mass, I think?11/19/2011
  Q: I am making those little beach scenes for my friends for Christmas. You know that ones with the ...
  A: It turns out that when I started grad school I worked in a field known as granular flow. The simple ...
physics11/18/2011
  Q: How do scientists isolate individual electons, neutons and protons so that these particles can be ...
  A: Based on their charge. But we can't isolate individual ones, they're identical particles. We ...
physics11/14/2011
  Q: "sir my question is if 12wires each of 1 ohm is arranged in a cube and 1 amp current is following ...
  A: It's the same as the potential difference between any path, but you never specified a lot of things. ...
Validity of an Internet source about radiation.11/9/2011
  Q: At: http://pissinontheroses.blogspot.com/2011/11/raw-downloadable-data-from-102611.html Mr. Potr ...
  A: First, his data kind of implies that he actually did the measurements, but very little about how ...
Rolling motion with off-center weight11/9/2011
  Q: I am working on a kinetic sculpture that uses rolling motion. I'll be using cylindrical shapes where ...
  A: Security rules prevent me from seeing where you're getting your guide to rolling motion, but ...
physics11/8/2011
  Q: sir i have a question that The masses of the three wires of copper are in the ratio of 1 : 3 : 5 ...
  A: The formula for the resistance of a wire is simple, R=pL/A where p is the resistivity of the ...
Validity of an Internet source about radiation.11/4/2011
  Q: At: http://pissinontheroses.blogspot.com/2011/11/raw-downloadable-data-from-102611.html Mr. Potr ...
  A: The cricticality at Fukishima resulted in the release of hydrogen gas. That resulted in a chemical ...
Fukushima and nuclear explosions11/2/2011
  Q: Can the crippled Fukushima atomic power plant in northern Japan produce a nuclear explosion? Can any ...
  A: First, let me preface this by saying that a reactor and a weapon are fundamentally different ...
a polytheistic universe?10/28/2011
  Q: This might be kind of an odd question. I am in an ongoing debate with a Christian (I am a ...
  A: Physics says nothing about religion at all. It does not prove one type of religion over any other. ...
light10/27/2011
  Q: When you polarize light in one direction..and since there are two components..E and B..does it mean ...
  A: No, it's not quite like that. You can't "cut out" a single component, they're related. You can ...
Van De Graaff generator10/18/2011
  Q: In Van De Graaff generator, What is the mathematical formula for the transfer of charge from the ...
  A: There is no such formula. It depends on many factors, like the charging comb, the place in the ...
big bang explanation10/6/2011
  Q: Probably really obvious but one I've not got my brain around. If you blow something up generally the ...
  A: First, the statistics are based on the first two concepts, you can't ignore them and hope to truly ...
big bang explanation10/5/2011
  Q: Probably really obvious but one I've not got my brain around. If you blow something up generally the ...
  A: The really brain-bending concept here is twofold: 1) There is no "center" of the universe that we ...
physics10/5/2011
  Q: what is friction ? its helpful or not ?
  A: Friction is a force due to contact between two surfaces that resists their motion. Of course it's ...
air powered vehicles10/4/2011
  Q: My partner and I are doing a science fair project on air powered vehicles and we would like you to ...
  A: Yes, but it's very complex exactly how. Yes, but it's not so straightforward. The leakage rate of ...
Gravity10/3/2011
  Q: Sir, in my science book it was written that the earth provides the centripetal force by its ...
  A: The acceleration of the Moon is towards the Earth, but acceleration is not the same as velocity. ...
Hi10/2/2011
  Q: Im studying in 12th. I want to know the reason for the early sunrise and late sunset?Can you please ...
  A: Not really important, given that refraction changes the sunrise and sunset by only the tiniest of a ...
freezing time of water9/29/2011
  Q: I know salt effects the freezing time of water, but does sugar and baking soda affect it to? If so ...
  A: Anything you dissolve in water has some kind of polar attraction to the water. So it will always ...
drinking bird - does it do work?9/28/2011
  Q: I have looked at all the equations for Work, and I am unable to find one that demonstrates that the ...
  A: I don't know what S is, since you have not defined it in either posting. But assuming that you're ...
drinking bird - does it do work?9/28/2011
  Q: I have looked at all the equations for Work, and I am unable to find one that demonstrates that the ...
  A: You have friction in the bearing, though low. Air resistance to motion as well, also low. And then ...
Megnetic field and its effect on protons9/27/2011
  Q: Sir / Madam please tell me which pole of a magnetic field attracts or repels +ve charge. If +ve ...
  A: They don't attract or repel charges. The magnetic field applies forces to moving charges, key being ...
Physics/Light Speed + LHC9/22/2011
  Q: On 4/1/2010 David Montiel answered a question about the ability to pass the speed of light. I just ...
  A: How is it right is not the current question. How is it not wrong is the current question. A mile ...
Thermodynamics9/22/2011
  Q: Sir, How can you best use a spoon to cool a cup of coffee? Stirring-which involves doing ...
  A: Stirring increases surface area and convects hotter liquid to the top as evaporation cools the ...
Old radium watch question9/21/2011
  Q: I saw a question from a couple of years ago about watches with radium dials/ hands and have a ...
  A: You are, kinda, because about 55% of everyone's natural radioactive exposure (the reason your dryer ...
Chemistry9/21/2011
  Q: I have few questions that i need help 1.in order to obtain a stable inert gas structure,electrons ...
  A: Yes, you're definitely confused. Part 1 makes absolutely no sense at all, what do you mean by that ...
I Want A simple Title in physics to make a research on9/20/2011
  Q: I Want A simple Title in physics to make a research on im a student and the Auc(American University ...
  A: What do you mean, just a title of an experiment? What kind of research topic area, and how simple ...
Parallel Universe Theory9/20/2011
  Q: I have a question regarding Multiverse theory or at least a part of it. I hope I can present my ...
  A: I think you meant the first stars and quasars were formed in the first several hundred million years ...
Electric Heating Element9/20/2011
  Q: I am trying to design an electric heating element for a new application my wife and I thought of. ...
  A: Yes, nichrome appears to be the material of choice here. Check out the wiki for general ...
Old radium watch question9/19/2011
  Q: I saw a question from a couple of years ago about watches with radium dials/ hands and have a ...
  A: For one thing, even if all the radium were scraped off and dumped randomly around your house, it ...
Proving Yarkovsky Effect in Science Fair9/19/2011
  Q: My name is Matt. I'm in the 8th grade and I'm working on a science fair project this year that ...
  A: Sorry for the delay. OK, how astophysics-related do you want the topic to be, and how much do you ...
Proving Yarkovsky Effect in Science Fair9/18/2011
  Q: My name is Matt. I'm in the 8th grade and I'm working on a science fair project this year that ...
  A: First, let me lead off with the bad news. This is a very bad idea (VERY bad) to present in front of ...
Silence9/17/2011
  Q: What is Silence according to science? ANSWER: "Silence" is the lack of sound waves, just like ...
  A: That must mean that their recordings showed a lack of sound waves. It's kind of like measuring ...
optics9/15/2011
  Q: When we wear polarized sun glass it cuts out either the E or B field ie if the E field is vertical ...
  A: It doesn't "cut out" one or the other, that would imply you can split up a photon. A photon is not ...
Outcomes of Weeble Set Ups9/14/2011
  Q: I'm interested in building a prototype which involves a weeble. I am wondering what the outcomes ...
  A: Depends on what you have to work with more than anything else. Concrete or cement is pretty dense, ...
Physics9/13/2011
  Q: i am a senior high student.. light sources and power supplies are easy to find..but diffraction ...
  A: You're really not giving me much in the way of list to go on. I'll pull an idea from the science ...
gravitational acceleration anti-hydrogen9/13/2011
  Q: Dr. Nelson, About 6 years ago I asked you a question about a model of the atomic nucleus I study. ...
  A: Welcome to the world of research...such experiments are still a work in progress, all these years ...
Quantium Physics question9/13/2011
  Q: I am not sure if my question is a physics question. If it is not, I apologize. I saw a pic of a book ...
  A: An entire course on quantum mechanics is far beyond the scope of this forum. It seems, from the ...
Outcomes of Weeble Set Ups9/12/2011
  Q: I'm interested in building a prototype which involves a weeble. I am wondering what the outcomes ...
  A: This is a matter of torque and rotational inertia. The absolutely ideal situation is to have a ...
where does it come from?9/12/2011
  Q: when we suck some water inside a syringe, the water is getting some height and as a result some ...
  A: You both have points. Your hand provides the energy to cause a pressure difference between the two ...
Physics9/11/2011
  Q: sir. this is me again.. i think it is much better if my invention is in the field of optics or ...
  A: That's even harder, I still have no idea what level of education you have or what equipment you have ...
Hello !9/11/2011
  Q: What is the difference between a generator and a dynamo? Why a dynamo is not necessarily a generator ...
  A: I suggest you see the basic Wiki on it: http://en.wikipedia.org/wiki/Dynamo It appears to be ...
circular motion = acceleration ?9/11/2011
  Q: circular motion = acceleration ? A piece of mass falling is defined by (mass x acceleration). Is a ...
  A: That is absolutely NOT the reason! It's because the x and y directions of motion are completely ...
Thermodynamics9/10/2011
  Q: Sir, Far above the Earth's surface the gas kinetic temperature is reported to be on the order of ...
  A: A person would die from decompression and lack of oxygen. While decompression might cause temporary ...
circular motion = acceleration ?9/9/2011
  Q: circular motion = acceleration ? A piece of mass falling is defined by (mass x acceleration). Is a ...
  A: No, you're asking about two dissimilar things. First, you're asking about the motion of the center ...
circular motion = acceleration ?9/7/2011
  Q: circular motion = acceleration ? A piece of mass falling is defined by (mass x acceleration). Is a ...
  A: No it is not. It is a disc. I believe you meant the motion of the disc. The spinning disc has an ...
hello..^0^9/7/2011
  Q: why the length of a solenoid is greater than its diameter ? Also how the north and south pole of a ...
  A: 1+2: The magnet poles are spinning. They're shaped to swing by the stator magnets as closely as ...
physics9/6/2011
  Q: can you help me to do an investigatory project that can be passed for a competition or a science ...
  A: Physics is an enormous subject, and rarely not eco-friendly. What sub-field of physics are you ...
Gravity9/4/2011
  Q: I'm over 40, this is not homework. At the science centre there's a vortex that you roll a ball down ...
  A: The ball's coefficient of rolling friction should have something to do with it, but not its density. ...
radioactive decay by protons ?9/4/2011
  Q: I would like to know why is not observed natural radioactive sources that produces protons, we only ...
  A: In fact, there are nuclei which decay by proton emission. Their lifetimes are ridiculously ...
hello..^0^9/3/2011
  Q: why the length of a solenoid is greater than its diameter ? Also how the north and south pole of a ...
  A: The length is not just greater, it's much greater. A solenoid assumes an infinite cylinder, which ...
Gravity9/2/2011
  Q: I'm over 40, this is not homework. At the science centre there's a vortex that you roll a ball down ...
  A: 1) Yes, that's what would happen. 2) That depends on the taper. It would have to balance out the ...
radiation9/1/2011
  Q: Human body emit its maximum radiation that is caused by the temperature of the human body at ...
  A: It's called blackbody radiation, see here: http://hyperphysics.phy-astr.gsu.edu/hbase/mod6.html ...
Question about Protons and Neutrons9/1/2011
  Q: Hey there! I am a geologist and I teach a few classes. One of my students asked me a question the ...
  A: Different isotopes are more or less stable than others because of the quantum mechanics of how a ...
physics8/31/2011
  Q: 1. when we see balmer series, lyman series it usually involves electron transition in electron ...
  A: Your first question makes very little sense. These lines don't "usually" involve transitions ...
science8/30/2011
  Q: why can't we exceed the speed of light
  A: It would require an infinite amount of energy to reach the speed of light. While not technically ...
sparks - arcing8/27/2011
  Q: My wife said she thought she saw sparks coming off the stove's electrical coil into the air. I said ...
  A: It's possible that you're both partly right. A sudden burst of fire from material on the hot stove ...
About electric field patterns8/26/2011
  Q: I'm currently studying electric field, but getting confused when I deal with questions about field ...
  A: Between two oppositely charged plates you get a relatively uniform field between and nothing ...
Model.(energy)8/24/2011
  Q: Sir. Its like eco-friendly ways to use energy . I want to make a heat pump.(working model) like when ...
  A: Geothermal energy then, pretty simple. You need something to pump the water, like an aquarium pump, ...
Power lines8/24/2011
  Q: I live on the 10th floor of a high rise building. The high tension power lines run about 50 metres ...
  A: 50m away? That's definitely plenty far to protect you from the weak EM fields of a power line, you ...
centripetal and centrifugal forces8/23/2011
  Q: It's my understand that centripetal and centrifugal forces are equal and opposite, am I wrong? If I ...
  A: Most people don't refer to a "centrifugal" force at all anymore, we just stick with the ...
weather baloons,8/23/2011
  Q: When a weather balloon rises it will expand..now these things unlike kids balloons go very high.Will ...
  A: That totally depends on how it's filled and how it's constructed. If it's not overfilled and it's ...
Exploration paradox8/18/2011
  Q: Yes, this is similar to the twin paradox, but with a few changes: Two brothers set off from earth ...
  A: You've got it all backwards, so stay with me here. First, if they embark on a journey of exactly ...
Shadow Matter and its implications8/18/2011
  Q: My name is Alexander,45,living in Toronto,Canada.I am Software Quality Assurance Analyst,but like to ...
  A: No, unless the "shadow matter" interacting with normal matter via gravity mimicked it in exactly ...
Stimulated emission8/18/2011
  Q: Suppose an electron is in a higher energy level and a photon comes along with an energy equal to the ...
  A: Again, you don't *need* a photon to cause an energy level change. The electric field of the photon ...
Exploration paradox8/18/2011
  Q: Yes, this is similar to the twin paradox, but with a few changes: Two brothers set off from earth ...
  A: You already have equations for time dilation. No, the problem here is that they do not take the ...
pulley8/15/2011
  Q: I have a machine that current is powered by a 50 cc 2 stroke engine. I use it to power a wench drum ...
  A: It'll give you more mechanical strength to use a smaller spool, but it'll move less quickly. So you ...
Capacitor EMP8/14/2011
  Q: Capacitor EMP Hello, I just need to know how to maximize an electromagnetic pulse. Is a flat coil ...
  A: Again, it's really more about the dielectric you use and the inductance of the circuit. So no ...
Capacitor EMP8/14/2011
  Q: Capacitor EMP Hello, I just need to know how to maximize an electromagnetic pulse. Is a flat coil ...
  A: Cellular processes are not that fast, you don't need the ultimate in EMP speeds and it doesn't ...
Virtual Particles8/12/2011
  Q: I'm having a hard time understanding virtual particles in empty space. E=mc^2 says that matter and ...
  A: Well, you definitely expressed the equation wrong. Mass is positive, even if it's antimatter. You ...
Capacitor EMP8/12/2011
  Q: Capacitor EMP Hello, I just need to know how to maximize an electromagnetic pulse. Is a flat coil ...
  A: First, why do you need to know how to maximize an EMP? Are you trying to knock out computers? That ...
billard balls8/11/2011
  Q: I am an avid pool player..there is a shot..the masse or curve ball.I hit the ball almost vertically ...
  A: The Coriolis force has absolutely nothing to do with this, it's pure friction and rotation of the ...
Invention of the Wheel - Circular Shape8/11/2011
  Q: Invention of the Wheel ---------------------- There are Two Wheelers, Three Wheelers and Four ...
  A: OK, I'm only going to answer this ridiculously simple question one more time. If the contact ...
Invention of the Wheel - Circular Shape8/10/2011
  Q: Invention of the Wheel ---------------------- There are Two Wheelers, Three Wheelers and Four ...
  A: Your wiki.answers.com link has all the answer you need. If you have tires (that's how we spell it) ...
car tint8/3/2011
  Q: Is there such thing as polarized windows for cars?
  A: There are tinted windows, but they're generally not polarized. It would be simple enough to make, ...
heat8/2/2011
  Q: what is intermolecular potential energy? what work does it do?
  A: Asking what work it does is pointless, energy is energy. Potential energy change is work. ...
Reflector systems8/1/2011
  Q: How does the design of the Hubble Space Telescope optical system differ from the basic Newtonian ...
  A: The Hubble was made wrong and had to have corrective optics installed on a series of spacewalks. ...
Photon vs neutrino7/27/2011
  Q: The photon is massless and travels at the speed of light. The neutrino has a very very small amount ...
  A: The word "neutrino" means "little neutral one." The photon is *made* of electromagnetic fields, the ...
Reflective Character Series - (Exact Replica of the Character/Letter/Alphabet in Mirror)7/27/2011
  Q: As similar to Reflective Number Series. we can also note down the Reflective character series for ...
  A: The arbitrary symmetry of letters and numbers as humans draw their characters is exactly that. ...
Mirrored Numbers - (Exact Replica of the Number) - Optics & Real Life Use ?7/26/2011
  Q: What i observe by looking at the Numeric Whole Numbers(Integers) in Mirror (Glass) Object are the ...
  A: Not that I know of. Specular reflection explains the first one and then we're pretty much done. ...
Mirrored Numbers - (Exact Replica of the Number) - Optics & Real Life Use ?7/26/2011
  Q: What i observe by looking at the Numeric Whole Numbers(Integers) in Mirror (Glass) Object are the ...
  A: Why are you asking a physicist and not a mathematician? No, this is not a class of numbers that I ...
radioactive dating now inaccurate?7/22/2011
  Q: I just learned that radioactive decay can be affected by outside forces, such as solar flares. if ...
  A: Have you read these papers? They all deal with electron capture by k-shell electrons in heavy ions ...
radioactive dating now inaccurate?7/21/2011
  Q: I just learned that radioactive decay can be affected by outside forces, such as solar flares. if ...
  A: No, radioactive decay itself is not affected by things like solar flares. Radiocarbon is also ...
waves7/15/2011
  Q: Hey Steve, In most diagrams and computer simulations of EM wave..lets take a photon...the E and b ...
  A: Of course the energy is stored in the E and B fields both, they both represent energy. They do not ...
ELECTRICITY7/13/2011
  Q: Steve I have a question. Could you explain in microscopic terms why 2.5 ohm is less than 4 ohm, ...
  A: Ummmm...2.4 is less than 4 because 2.4 is less than 4. There's no microscopic anything about any of ...
electrons in metals7/12/2011
  Q: A bonded electron when it "jumps" orbits absorb/emit discrete amounts of energy.What abt.when it is: ...
  A: a) Yes b) You're oversimplifying. The wavefunction overlaps between many atoms, it's distributed ...
physical science7/10/2011
  Q: can you explain why sound travels faster in stone,and water than in air?
  A: The speed of sound depends on the collisions between molecules. Connected molecules (like liquid or ...
relation between mass & hight7/9/2011
  Q: sir when a body of mass 'm' is dropped from a hight 'h' then the potential energy 'm*g*h' is ...
  A: I just explained *why* it's independent of mass (this doesn't account for the air resistance of tiny ...
Nomenclature7/8/2011
  Q: Could u pls tell me by what name we designate the following effect. "If we suddenly release a ...
  A: Ummmm...of course it's related to thermodynamics, it's just a definition in thermodynamics. You ...
ball in motion.7/7/2011
  Q: In golf for example if a ball is rolling on the green and it hits the pin, is it possible for it to ...
  A: Further than if it rolled by? Only if it was rolling uphill and bounced back downhill, according to ...
Physics/Homework Help7/5/2011
  Q: A student swings his keychain around in a circle. What is the source of the centripetal force for ...
  A: I don't answer homework questions, your title says Physics/Homework help. Why would you ask me ...
Mechanics7/4/2011
  Q: I want to know that how to calculate the total number of wraps of a finite length coil of given ...
  A: Ummm...we need a real problem, rpm has nothing to do with geometry. A finite length of wire and a ...
Measuring the speed of light7/3/2011
  Q: In Roemer's method of measuring the speed of light, he found that the orbital periods of Io were ...
  A: Not shorter, later. Which is accommodated by the face that Earth is twice as far away at ...
Physics7/2/2011
  Q: I have learned the equation of Newton's gravitational law and I wonder how Newton calculate the ...
  A: Observationally. It's a little different than experimentally, where you get to perform controlled ...
Physics7/2/2011
  Q: I have heard that the F-117A stealth fighter is specifically designed to be a non-retroreflector of ...
  A: A massive combination of non-metallic materials and asymmetric plates in the design give it its tiny ...
possible explanation for dark matter7/1/2011
  Q: I am not a physicist so if this makes no sense then dont waste your time. It strikes me that ...
  A: No, because of the distribution of galactic spins and galactic cluster velocities, they match with ...
water to ice7/1/2011
  Q: I was wondering if you could help me,I was wondering when freezing water to make a solid (ice) is it ...
  A: I'd say you need to start by boiling the water to degass it, boiling all the air out. Then let it ...
Spinning a car around 90 degrees - force required6/30/2011
  Q: I am a lawyer acting for a Claimant in a road traffic accident, where there is a liability dispute. ...
  A: You're asking for force and speed, without any testing or any of the parameters you actually need to ...
broken window6/29/2011
  Q: 1st off I live alone, I was in my front room watching TV when I heard a loud sound(something hitting ...
  A: While it is slightly possible that flexing caused glass to fall on the outside, they absolutely ...
speed of a car6/29/2011
  Q: How fast would a car have to be going to throw a 200 lb. body on a bicycle 100 feet?
  A: The weight of the body and the fact that it's on a bicycle is relatively immaterial. I can't answer ...
spin altering6/29/2011
  Q: http://www.sciencedaily.com/releases/2011/06/110605132431.htm 'because photons at the right ...
  A: Yes. Research how an MRI (also known by its original name, NMR) machine works. A photon has an ...
Color Theory6/24/2011
  Q: Why have most models for primary colors been in 3 colors? Like cyan, magenta, and yellow, or red, ...
  A: It is indeed because the human eye has 3 basic cones. You should investigate the vision of the ...
On which principle is the Electrostatic Radiant Impulse concept of Nikola Tesla based ?6/21/2011
  Q: How are you ? Do you remember me ? I will not give up till I understand the secrets of the ...
  A: There aren't really secrets to electromagnetic field theory, just a lot of math and that requires a ...
physics/mechanics6/20/2011
  Q: I have a problem where I will vertically drop a 2 lb. steel ball onto a thin steel plate from ...
  A: You can't! There's no way to compute that without knowing tons and tons of parameters about the ...
x ray6/20/2011
  Q: I have been working in x ray room last 2 years. x ray capacity is 300kv and 7.5ma. there is also ...
  A: Presumably if you were an x-ray tech then you had a radiation badge...therefore you should know ...
Designing Reverse Gear/s for Trains i.e Locomotives, Ships and Aeroplanes.6/19/2011
  Q: Is it possible to design Reverse Gears for Locomotives, Ships and Aeroplanes OR Theoretically and ...
  A: Ummm...floatation of a ship has nothing to do with its thrust direction. And train engines run in ...
Movement of CO2 and Cooling Gases that Create a Vacuum6/17/2011
  Q: Nelson, I am a novelist trying to set a death mystery scene utilizing the chemistry and physics ...
  A: Caves can fill with weird gases naturally which could preserve bodies. Many caves have multiple ...
Engines6/17/2011
  Q: I used to be able to start my car..1965 Datsun by engaging 1st or 2nd gear ...manual ...
  A: I'm a nuclear physicist (), not an expert on cars, so this is really a little outside my experience. ...
Laser6/17/2011
  Q: In Helium-Neon laser, why is the ratio of He to Ne 4 to 1? (as in why does He need to be supplied ...
  A: I'm not a laser guy, but I'm guessing it's what we in the business of experimental physics call ...
Movement of CO2 and Cooling Gases that Create a Vacuum6/16/2011
  Q: Nelson, I am a novelist trying to set a death mystery scene utilizing the chemistry and physics ...
  A: If you're creating carbon monoxide, you don't have to worry about sealing the cave. CO will bind to ...
Designing Reverse Gear/s for Trains i.e Locomotives, Ships and Aeroplanes.6/16/2011
  Q: Is it possible to design Reverse Gears for Locomotives, Ships and Aeroplanes OR Theoretically and ...
  A: Most of the operating conditions you mentioned will be relatively immaterial to the vehicles you're ...
energy conservation6/16/2011
  Q: ive got a project to make a car that can move as fast as possible. it should be made out of a body ...
  A: Ahh, then lowering friction and air resistance are your only concerns! Make sure you pay attention ...
Positronium6/15/2011
  Q: My question concerns positronium. Literature speaks of a bound state of electron and positron, ...
  A: It doesn't matter what kind of answer you want, you get the answer physics gives you. And quantum ...
Designing Reverse Gear/s for Trains i.e Locomotives, Ships and Aeroplanes.6/15/2011
  Q: Is it possible to design Reverse Gears for Locomotives, Ships and Aeroplanes OR Theoretically and ...
  A: This isn't really a physics question, it's engineering. You can reverse any thrust. For a plane, ...
physics science6/14/2011
  Q: Particle accelerators are devices that speed up charged particles in order to smash them together. ...
  A: Tricky, because they don't last very long. But in that brief time, scientists can observe how much ...
Resonance patterns6/6/2011
  Q: I understand (from a course in the Philosophy of quantum mechanics I am currently attending) that ...
  A: http://ocw.mit.edu/courses/physics/8-04-quantum-physics-i-spring-2006/ If you're looking for ...
sci-fi space travel calculations6/4/2011
  Q: I am working on a science fiction story, involving travel to the Oort Cloud. I have almost no math ...
  A: The problem is that it gets far, far more complex when you go to relativistic speeds. You can't ...
Resonance patterns6/3/2011
  Q: I understand (from a course in the Philosophy of quantum mechanics I am currently attending) that ...
  A: "Resonant patterns" would correspond to the solutions to wavefunction equations (the Schrodinger ...
Bouncing up and down6/1/2011
  Q: First of all, I thank you for offering freely to help enlighten people. I recently bought myself a ...
  A: You're confusing mass (which is constant), weight (which depends on gravity), and force (which can ...
Egg drop Physics5/31/2011
  Q: Im doing the egg drop and need help with some questions... What can you conclude or what is ...
  A: Well, let me just say they're basically wrong without accounting for a lot of factors and that ...
Egg drop Physics5/30/2011
  Q: Im doing the egg drop and need help with some questions... What can you conclude or what is ...
  A: You only included the one, graph B. Obviously the other two are integrals and derivatives of this ...
RE: car crash investigation5/29/2011
  Q: My name's Jack. I'm doing my car crash investigation. i need to prove a 2 equations which is in ...
  A: No, actually, I can't tell you who was and was not lying. I'm not a psychic. I don't know the ...
Two Big Queries5/26/2011
  Q: If you have a golf ball falling to earth the earth pulls on it with force "A". The golf ball pulls ...
  A: 1) You have Newton's 3rd law totally wrong, the ball (no matter the size) exerts the same force on ...
electricity5/26/2011
  Q: I JUST HAPPENED TO NOTICE THAT THE BULB IN MY BEDROOM GOT HOTTER AS IT GREW DIMMER OVER THE YEARS. ...
  A: Light bulbs emit about 90% of their energy as heat, not light. If it got dimmer over the years then ...
RE: car crash investigation5/25/2011
  Q: My name's Jack. I'm doing my car crash investigation. i need to prove a 2 equations which is in ...
  A: In any case like this I can never speak on behalf of the university I work for, but I can always ...
uncertainty principle5/24/2011
  Q: my question is about uncertainty principle.i was reading Feynman lecture where he had described(in ...
  A: Again, missing the point of scale. A detector is made of billions (or more) of atoms. An electron ...
uncertainty principle5/24/2011
  Q: my question is about uncertainty principle.i was reading Feynman lecture where he had described(in ...
  A: No, you're pretty much missed the point completely. Any detector that sits at one of the holes ...
egg drop5/14/2011
  Q: I have an egg drop project coming up in my class. I am given 10 sheets of paper and 1 meter of duct ...
  A: First, you might turn the paper into strips for streamers to keep it from turning over. Also, use ...
physics5/12/2011
  Q: Is there a way to separate biodegradable from non-biodegradable materials using machines?
  A: This question is more about engineering and materials than physics. But I'll give it a crack, even ...
infrared radiation5/10/2011
  Q: When people use special technology to take a picture of someone reflecting their electromagnetic ...
  A: Well, fascinating question Gena. It totally depends on the camera. I have a camera that *only* ...
Radioactivity5/9/2011
  Q: I read with interest your assessment of the negligible health effects likely from radiation exposure ...
  A: For one, the darkened room only dilates their pupils and lets more light in, it doesn't hamper the ...
Evidence that the universe is expanding5/9/2011
  Q: It is my understanding that the evidence that the universe is expanding is that the furthest ...
  A: No, it's straight-up Doppler shift. We measure the precisely-known shift of wavelength of specific ...
Physics - Safety of a Swimming Pool5/9/2011
  Q: I was wondering if their was any possible physics experiments linked to the safety of a swimming ...
  A: Safety? That's not really physics, and pressure has little to do with pool safely. Pressure is ...
electromagnetism5/8/2011
  Q: when you drop a metal bar from a height through a closed loop, an EMF is induced. my question is how ...
  A: You just capture the trace on the oscilloscope and measure the induced voltage vs. time. You ...
electromagnetism5/6/2011
  Q: i need help explaining to me an experimental way i could proof electromagnetism in the lab. so, i ...
  A: How exactly it depends on the geometry and the magnet strength are very complicated, depending on ...
electromagnetism5/6/2011
  Q: i need help explaining to me an experimental way i could proof electromagnetism in the lab. so, i ...
  A: So an EMF is another word for voltage. Read the voltage off the vertical scale of the scope. Then ...
Career Physics, Advice5/5/2011
  Q: Steve: My name is Jim Ray. I am a student of physics at Indiana University. To explore the ...
  A: This really sounds more like research for some kind of report than basic questions. A career ...
Question about the Chernobyl Disaster and Physics5/4/2011
  Q: I was wondering if there was a connection between the Chernobyl Disaster and any part of Physics as ...
  A: How can you write a detailed report without knowing enough physics to answer this question yourself? ...
GPS Idea5/4/2011
  Q: Just the same I want your input on both its marketability and if the technology would be easy enough ...
  A: I know absolutely nothing about marketability. I can tell you if it has half a chance of working if ...
Local GPS5/3/2011
  Q: I believe you said you could help me with my GPS idea sometimes back? ANSWER: Well, you'll have to ...
  A: Getting a patent is a process that takes years and costs in the thousands of dollars. It has to be ...
Local GPS5/3/2011
  Q: I believe you said you could help me with my GPS idea sometimes back? ANSWER: Well, you'll have to ...
  A: I recall. It would be insanely expensive to build something so special-purpose as localized GPS. ...
Lorentz force and relativity4/26/2011
  Q: Consider two point charges each moving with velocoty, v, on the same plane along perpendicular ...
  A: I don't understand why you even asked the first question, defining a charge density x has to be ...
Laser ablation4/26/2011
  Q: I have been researching laser ablation on the internet for a project I am working on, but I am ...
  A: Seems like you could do that, but the optics behind it are far beyond me for what you'd need to ...
Lorentz force and relativity4/26/2011
  Q: Consider two point charges each moving with velocoty, v, on the same plane along perpendicular ...
  A: So since those should cancel out (no, I didn't do the calculation) and the calculated force should ...
blood pressure/atmospheric pressure4/26/2011
  Q: I used to study physics in high school and a friend recently put the question to me regarding blood ...
  A: No. In a vacuum, you'd be dead. For absolute pressure, you have to add exterior fluid pressure. ...
Lorentz force and relativity4/24/2011
  Q: Consider two point charges each moving with velocoty, v, on the same plane along perpendicular ...
  A: You're forgetting that this problem involves *changing* magnetic fields as well as relativity. ...
Inelastic relativistic collision4/23/2011
  Q: !! I still have a doubt about inelastic collisions in relativity. I think that DeltaK (variation in ...
  A: You really need a course in relativity, and to stop asking me questions that are the very ...
Relativity4/23/2011
  Q: I am an Italian boy who is trying to remedy his ignorance in natural sciences and studies physics by ...
  A: 1) In your correction you write that it's an isolated system where an inelastic collision happens, ...
Relativity4/22/2011
  Q: I am an Italian boy who is trying to remedy his ignorance in natural sciences and studies physics by ...
  A: 1) You reversed your position on relativistic mass. As I said, it can change, since energy can be ...
Relativity4/22/2011
  Q: I am an Italian boy who is trying to remedy his ignorance in natural sciences and studies physics by ...
  A: I don't have time to check this over carefully, but I think I can help: 1) Not really. You can ...
Elec&Mag4/17/2011
  Q: Does inductance of a coil depend upon temperature like resistors? Can it be theoretically proved as ...
  A: Only a tiny bit, as the geometry of the coil expands and contracts with temperature. Theoretically? ...
electricity4/16/2011
  Q: What is the basic difference between ballistic galvanometer and suspended type moving coil ...
  A: They're largely the same. The large moment of inertia of a ballistic galvanometer, however, allows ...
light intensity within a hologram projection.4/13/2011
  Q: I have a question about holograms and light/lasers. I know that light generally travels in a ...
  A: Well, this is a rather simplistic view of holography, which involves 3D interference. It's not as ...
3rd law of motion4/13/2011
  Q: is 3rd law also follow in cricket???means vn ball came 2batsman and batsman pushses....dn action and ...
  A: Yes, it *always* works. The ball may push as hard on the batsman as the batsman does on the ball, ...
Quantum indeterminacy4/12/2011
  Q: First of all I cannot find any expert who would mention quantum physics as his main area, so i ...
  A: Yes, we refer to this as the collapse of the wavefunction. This is the "orthodox" position in ...
2D Mass4/9/2011
  Q: Is it possible in our 3D world for a particle of Mass to be only 2 dimensional ? Thanks, Craig
  A: "Our 3D world" just implies that there are three spatial coordinates for the particle to be located ...
Fish4/3/2011
  Q: Maybe silly question, but was wondering what would happen to a fish in say a Basketball filled with ...
  A: Fish are neutrally buoyant. They would float with the water and experience its same acceleration. ...
Interview for Science Research4/2/2011
  Q: I want to ask you a few questions for my science research. Please reply as soon as possible. 1. Do ...
  A: First, what is a negative material? Are you referring to something in the triboelectric series? ...
kinematics/waves?3/31/2011
  Q: My professor said today in class that two cars going the same speed at a distance from each other ...
  A: If they decelerate uniformly then they stay at the same relative velocity and your professor is ...
fluids3/30/2011
  Q: How does water from a tap fill a bucket that is already a quarter full as in what position of the ...
  A: You'll have to draw me a picture. If I have a tap pouring from above a bucket which is 1/4 full it ...
Nuclear Physics3/30/2011
  Q: I was wondering that if in the case of the Fukushima Nuclear Plant having a triple meltdown, not ...
  A: Wow! You have a severely overinflated impression of what humans have built and our power to destroy ...
car crash3/20/2011
  Q: A 1 ton 2002 Ford van weighing 9000 lbs travailing 55 mph tee boned a 98 Mitsubishi Montero weighing ...
  A: You can't calculate that, and anyone wh says they can is lying to you. 42 feet is a long way, so I ...
Nuclear Physics Questions3/19/2011
  Q: I'm a undergraduate student with a strong interest in science, returning to school after recovering ...
  A: OK, I can gauge your level of understanding by the statement "how it behaves when released into the ...
Entropy3/18/2011
  Q: How can we theoretically conclude that entropy is a state function.Can describe the mental steps ...
  A: State function just means it doesn't matter how you assembled the system. They generally describe ...
Crystal Reaction to Electrical Current3/18/2011
  Q: I'm curious if there is a known crystal or mineral type that emits light when an electrical current ...
  A: Not that I know of, perhaps you can ask a geologist. Generally crystals are insulators and not ...
electric field penetration3/17/2011
  Q: We know from theory that when the operating frequency of an antenna is higher, then the penetration ...
  A: Well, dielectrics are funny, based on their measured material properties. For example, visible ...
law of radioactive decay3/16/2011
  Q: I have published this hypothtical paper on scitopics.com and would appreciate if you could solve ...
  A: It's NOT universally applicable because it implies (by calling it a Law) that it's an absolute and ...
Noetic Science3/15/2011
  Q: I'm a sophomore in Saudi Arabia and I've been assigned to write an article on Noetic Science for USA ...
  A: Thoughts are formed of chemical patterns changing, not physical things. Technically there's a ...
law of radioactive decay3/14/2011
  Q: I have published this hypothtical paper on scitopics.com and would appreciate if you could solve ...
  A: Well, you're slightly off and certainly haven't discovered anything original. In my doctoral ...
Nuclear blast radius/fallout3/14/2011
  Q: Nelson, Hello! I am writing a speculative fiction book, and I would like to know about the blast ...
  A: There's not hard and fast "blast radius." See here: ...
Impact of fallen objects3/13/2011
  Q: How much force is created when a 200 pound weight is dropped 10 feet? The specific situation is ...
  A: There's no way to calculate the "force." There's an impulse you could calculate, but a maximum ...
Aero Bike3/11/2011
  Q: Please, may I ask you to comment on my idea for the Aero Bike? I want to store energy in the frame ...
  A: It's very similar in concept to pneumatic hybrid cars, of course. They were supposed to hit the ...
cosmic rays3/11/2011
  Q: We are bombarded by cosmic rays every sec.how come it does not interfere with our TV,mobile and ...
  A: One spurious event every few seconds in the midst of GHz communications systems aren't going to ...
ferrofluids3/8/2011
  Q: For my third year expirimantal course, im making a ferrofluid 'hour glass' to find out the viscosity ...
  A: Most of the physics of ferrofluids would be published in professional journals. Because they're ...
mechanics2/28/2011
  Q: earth is bulging at equator nd flattened at poles is because of centrifugal force how??
  A: Technically no, it's called centripetal force. But the Earth is spinning, and a force is required ...
Expectation of Braking time for a car2/25/2011
  Q: This is by no means homework related, just to settle a disagreement. What is the reasonable ...
  A: Not really, you didn't even ask me what was reasonably expected. A stopping distance? Do you have ...
Work Problem2/25/2011
  Q: A block of mass 3 kg, which has an initial speed of 5 m/s at time t = 0, slides on a horizontal ...
  A: Your question presumes to command me to "Answer in units of m." I have an alternative proposal. ...
Forces acting on surfaces2/25/2011
  Q: I am an Italian boy who is trying to teach himself the basics of physics. I studied at a classical ...
  A: Yes, the forces exerted are equal for a static situation. This is one of Newton's laws, and it is ...
falling object exerts ? force---2/24/2011
  Q: I am hardly a student of physics or any sort of experienced in those equations, although I am quite ...
  A: You can, ignoring air resistance, calculate the velocity it would hit after falling that far. It ...
mechanical seismograph2/24/2011
  Q: I have an assignment from my teacher and that's about "the relationship between mechanical ...
  A: Well, for an overview, see here: http://www.thetech.org/exhibits_events/online/quakes/seismo/ ...
GPS2/23/2011
  Q: Are you the expert I contacted involving local GPS? I think I met the MAX number of followups ...
  A: I guess I was. GPS is complex because there are satellites involved. You could create a local GPS ...
rotation2/22/2011
  Q: I want to ask about a comman observation which has an unanswered question. i want to know why the ...
  A: The frames of the video are captured quickly and at specific intervals. If those intervals coincide ...
How to solve complex problems2/20/2011
  Q: I was wondering if you could provide some advice on how to solve problems.When solving problems i ...
  A: Interest in learning physics is ultimately important to the learning process, it provides the ...
How can I produce strong and quick pulses ?2/20/2011
  Q: Nelson, Here I am again and would like to ask you a simple question, not like the others. Hmm, You ...
  A: a) No, you will create a back EMF in the motor, inhibiting the current and voltage you create. ...
electronics,differaction2/20/2011
  Q: sir why cable Tv is preffedred? Also tell how transmission of radio waves can be heard in hilly ...
  A: I have no idea why it's preferred or if it's preferred, perhaps you should refer that to a ...
Ping pong balls2/20/2011
  Q: which surface does ping pong balls bounce higher on?? The surfaces are floorboards, tiles, grass, ...
  A: You can read my name and qualifications on my profile on this website. It wouldn't hurt you to do ...
double slit2/19/2011
  Q: What will happen if I keep a metal plate in the places where dark fringes are formed in Young's ...
  A: The change is in the probability that the photon would hit the metal or not hit the metal. If the ...
Local GPS?2/19/2011
  Q: How does GPS work exactly? When I was a kid I remember having toys that were designed to resembled ...
  A: Many cell phones have locators which use cell towers as a version of GPS without actually having GPS ...
random2/18/2011
  Q: How come some days a rainbow forms on my wall other times it doesn’t? Why cant eyes see infra red ...
  A: That's the clouds and/or the angle of the Sun as it changes during the year. What kind of rainbow, ...
physics2/18/2011
  Q: why does a heavy object accelerated upward returns to the same point at the earth from where it is ...
  A: It doesn't, actually, not quite. I mean, satellites orbit because they're projected upwards so fast ...
bouyancy2/17/2011
  Q: my friend and I got into quite an argument over the bouyancy object that is sealed air tight. He ...
  A: You're both wrong. Pressurizing it will increase the air density, increasing the weight. Foam will ...
questions torturing me2/17/2011
  Q: Steve Nelson, Can you tell me how to ask questions properly from Professors? It always happens that ...
  A: Don't feel awkward, just ask your questions. You'd be shocked at the percentage of your classmates ...
questions torturing me2/17/2011
  Q: Steve Nelson, Can you tell me how to ask questions properly from Professors? It always happens that ...
  A: Physics professors value specificity in questions. Be specific about exactly what you want to know, ...
Local GPS?2/17/2011
  Q: How does GPS work exactly? When I was a kid I remember having toys that were designed to resembled ...
  A: Yes, it could be used for that. GPS, the details of how it works are incredibly complex, even has ...
sci fi2/16/2011
  Q: Good Day to you Sir. I have a question which migh be a bit silly. From a physics standpoint, are the ...
  A: Possible or plausible? Possible with current technology, absolutely not. Someday? I mean, I would ...
Particle Accelerator2/15/2011
  Q: First of all , I want to say hi , my name Azzam Hamad from Syria , Hims and I am a student in the ...
  A: Advising you on building a particle accelerator is well beyond the scope of this forum, especially ...
physics2/15/2011
  Q: My question is how can I calculate the mass of the sphere and the pulling force or atmospheric ...
  A: The force and radius are directly related. Atmospheric pressure is equal to p=101,000N/m^2. If you ...
physics2/14/2011
  Q: I want to know all about the phenomena of sticking two half hollow sphere together when air is ...
  A: This is just a historical demonstration of the strength of air pressure when a vacuum is applied on ...
cars on ice2/14/2011
  Q: Going the same speed , would a longer or shorter wheel based vehicle spin faster on ice? ANSWER: ...
  A: I told you that the linear speed won't matter relative to their rotational rate. As a practical ...
Two Slit Experiment2/13/2011
  Q: What happens to the results of this experiment if the source is biased towards one slit over the ...
  A: The bias will alter the interference pattern according to the strength of the wave towards each ...
Who created God?2/10/2011
  Q: You say that as we don't know what came before Big Bang, there must be a God. But who created God? ...
  A: I said no such thing about there must be a God. Therefore, your question is meaningless. And I ...
Dent in Mass2/9/2011
  Q: A dent that occurs in a piece of Mass. How is that defined via Physics. Mass x Distance ? Mass x ...
  A: A dent being formed would be the rate of change of the volume in the mass. Again, NONE of the ...
Are you an atheist?2/9/2011
  Q: Are you an atheist?
  A: This is not a physics question, and my personal religious beliefs are absolutely none of your ...
Crumple zone2/7/2011
  Q: I was wondering if you could answer mywhat will make a naked egg remain intact from falling after 10 ...
  A: Impact forces are what remove the energy from the moving egg. Force multiplied by distance is equal ...
Phase change in a metal?2/6/2011
  Q: Back in the late 60s I was microwave supervisor at the NASA ATS transportable ground station in ...
  A: Interesting question. Something would have to have either released energy or released gases. I ...
Impact from deer caused cracked windshield2/4/2011
  Q: I recently got hit by a deer on the left side of my car. From the hit, there is damage all along the ...
  A: While I have to attach the disclaimer that I in no way represent my university when I give you my ...
heat2/2/2011
  Q: What would happen if bridges are not supported by roller what is the role of roller?is its ...
  A: It would induce thermal stress if not supported by some kind of moving structure. Usually there are ...
physics- magnetism1/31/2011
  Q: What causes magnetism? I understand what causes another force such as gravity, that it is just ...
  A: Magnetic fields are caused by fields...heh, I just wrote something that totally made no sense. ...
physcis1/30/2011
  Q: we usually say that mobile should be switched off near petrol pump.what is its reason.what would ...
  A: That's a myth, gas pump fires are caused by static electricity from people getting back in their ...
two slit experiment in a vacuum?1/30/2011
  Q: i was thinking, maybe in the two slit experiment the electron that was being fired at the two slits ...
  A: Ummmm....to conduct the experiment in the first place you had to do it in vacuum. Seriously, ...
inductor1/29/2011
  Q: what is meant by inductor has less resistance but high self inductance?is every coil like rehostate ...
  A: This is a spaghetti mess of questions, I'll approach them in order. Less resistance than what? High ...
Spin1/29/2011
  Q: Please see the following links 1.http://en.wikipedia.org/wiki/Stern%E2%80%93Gerlach_experiment ...
  A: I think you're confusing orbital angular momentum with intrinsic angular momentum. You keep ...
ultrasound and ice dams1/29/2011
  Q: Previously you stated that using ultrasound would be 'excessively dangerous' for ice removal. Why? ...
  A: I don't recall that answer, but I get a lot of questions. The power levels required would be ...
Radio Waves1/26/2011
  Q: I was wondering how do you protect yourself from micro or radio waves? I live in an apartment and I ...
  A: I've gotten questions like this before about sound devices and microwave devices and neighbors. ...
nature of time1/22/2011
  Q: I have heard things said such as that all time already exists but that we just haven't gotten to ...
  A: Physics doesn't define time in such a way, but as a fourth dimension of space-time. Certainly not ...
Is the Electromagnetic stationray wave, longitudinal in its nature ?1/22/2011
  Q: Can you still remember me ? I am still researching and found some interesting results ! There was a ...
  A: You mean a standing wave, not a "stationary" wave. A standing wave is made of multiple traveling ...
Electricity1/21/2011
  Q: Two small plastic balls hang from threads of negligible mass. Each ball has a mass of 0.33 g and a ...
  A: The asking of this question indicates that you don't read profiles. Mine says I don't answer ...
generators1/19/2011
  Q: How does rotational energy translate to electric generators? Say i have a wind turbine. Do i create ...
  A: Of course it will generate more energy the faster you spin it, but there's not hard and fast ...
capacitor1/18/2011
  Q: why ac can pass through capacitor while dc can not pass through it?
  A: Well, that's a dramatic oversimplification, isn't it? If you apply a DC voltage to a capacitor it ...
Reflection from water1/17/2011
  Q: My email address is a clue to my age.But I'm still curious. My pond water is perfectly clear & deep. ...
  A: This forum doesn't give us your email address, so I have no idea what comment meant. It's not a ...
working model1/9/2011
  Q: "i am 14 years old and i have to make a working model on any of these ...
  A: Why the quotes around your question? If you're just cutting and pasting someone else's question, ...
Oar Boats1/8/2011
  Q: My history teacher was talking about ancient battle ships, and he said that one of the battle ...
  A: The statement is erroneous. You'll have a slightly different amount of power due to the fluid ...
Physics question1/8/2011
  Q: "A mass of 323 g connected to a light spring of force constant 24.5 N/m oscillates on a horizontal, ...
  A: You have a physics textbook. It has all sorts of formulae by which you could arrive at the answer ...
another vehicle crash1/8/2011
  Q: I recently hit an electric pole and broke it. Is there a way to determine the speed my vehicle was ...
  A: There's a way, but you won't like it. Take a bunch of cars and crash them in exactly the same way ...
Bending of space1/7/2011
  Q: I'm trying to understand what it means to bend space itself. It seem counterintuitive since space ...
  A: The distance within the empty distance itself, where light or particles might pass through, is ...
Physics1/7/2011
  Q: Good day Sir! How can we make a ripple tank for our Physics project?
  A: You just make a shallow glass or clear plastic bottomed tank with some water, some cloth to absorb ...
car crash1/6/2011
  Q: I was recently involved in a collision on a motorway. We were travelling between 60-70mph and ...
  A: I'd need quantitative data to prove anything quantitative about the accident, sorry. In this case I ...
black holes1/5/2011
  Q: With the discovery of an expanding universe where everything will eventually disipate, what will ...
  A: Regardless of the expansion of the universe, black holes are gravitationally bound together. ...
Bending of space1/4/2011
  Q: I'm trying to understand what it means to bend space itself. It seem counterintuitive since space ...
  A: Well, quantum-mechanically speaking, space is totally full of particle/antiparticle pairs which are ...
properties of matter1/3/2011
  Q: i got doubt in this topic...why maximum height of mountain is only 10km??..it shud b ...
  A: The pressure at that depth corresponds, if you look at the units, to an energy density. That's why, ...
Sound1/1/2011
  Q: I am a student currently studying in a secondary school also known as high school. It's about my ...
  A: The power of "the sound produced" (you don't specify by what) depends on how it is produced. A horn ...
a simple but confusing question12/31/2010
  Q: what is the cause of gravity??
  A: Gravity curves space. A simplification is probably necessary, so I'll use an initial image I ...
Detecting Alpha and/or Beta radiation12/31/2010
  Q: I hope you don’t consider this an academic or professional question? I have no academic credentials ...
  A: Excerpts are to be treated with appropriate caution. There are at least three *huge* mistakes I see ...
Detecting Alpha and/or Beta radiation12/30/2010
  Q: I hope you don’t consider this an academic or professional question? I have no academic credentials ...
  A: My critical evaluation starts on several fronts. Setting aside the bad spelling and grammar, the ...
Do you believe in this?12/29/2010
  Q: Do you believe in psychic/spiritual healing, ESP, haunted houses, demonic possession, ghosts/spirits ...
  A: Believe? That would imply that it was obvious, like gravity, which I think we all believe in. Am I ...
loght12/28/2010
  Q: Sir, A photon has no mass but it has momentum..how? Since momentum is mass x velocity.Thanks
  A: Light has no rest mass, but has energy. For light, you need to consider relativity and wave ...
nuclear physics12/24/2010
  Q: What are main differences between beta particle and electron? is there difference between ionization ...
  A: Your question is quite meaningless. Beta particles have a decay energy given to them during the ...
physics12/22/2010
  Q: SIR, CAN YOU JUST EXPLAIN THE MOTION OF CENTER OF MASS OF FIRE-CRACKERS WHEN THEY EXPLODE IN AIR. ...
  A: Yes, it's quite simple. The horizontal motion of the center of mass of a firecracker does not ...
electricity and phase transitions12/20/2010
  Q: Could electricity do the same thing as temperature and pressure to a atom, say could electricity ...
  A: Electricity can add energy, but these concepts are separate and you're mixing them. Passing ...
physics12/17/2010
  Q: find the value of an angle theta an inclined plane for which a=g
  A: HAAAHAHAHAHAHAAAA!!! Sorry, I just love it when the answer to an obvious homework question is soooo ...
Electroscope12/17/2010
  Q: I'm trying to figure out what exactly is an electroscope and how it works, what is the meaning of ...
  A: Wow, there are tons of pages on wikipedia which actually (I just searched) actually describe these ...
science12/16/2010
  Q: A cement compound CaO.Al2O3.10H2O gives certain peaks when using the powder diffraction method. The ...
  A: You may get that if the form of the crystal remains the same, however, crystals like this are ...
Washing machine12/12/2010
  Q: how do you calculate the energy efficiency of a Washing machine?!
  A: Well, that's a difficult question. For a washing machine you don't have measurable outputs like ...
Physics of a verticle bouce with acceleration12/11/2010
  Q: I understand that if i am moving at a set speed of say 45 mph and drop a ball out the window that ...
  A: The sheriff called me the other day and asked a similar question, actually, involving shell casings ...
question12/11/2010
  Q: How do I Calculate the period of a ball that is tied to a string with a length of .3 meters that ...
  A: Since this is the third time you've tried to ask me this obviously homework question, I'll tell you ...
Einstein12/10/2010
  Q: I have a good reason for not wanting to believe in Einstein's relativity/special relativity ...
  A: First, FTL travel is possible via many gravitational phenomena, even according to Einstein's field ...
Correct Solution for Power Problem12/8/2010
  Q: Me and my physics teacher are at a disagreement for how to solve a physics problem on a previous ...
  A: Your method is not quite correct, but your method is a lot closer. Your physics teacher's method ...
Thermal columns, Exciting Molecules and other Physics12/4/2010
  Q: Hey Steve, I have a question regarding thermals and other molecular sciences. First a ...
  A: Sorry for not getting back to you faster, but it's finals time here and we're really under the gun. ...
electric waves12/3/2010
  Q: what happens when a em wave hits a electron or hits an atom does it give the electron charge or ...
  A: No, the electromagnetic wave may or may not interact with the electron, but it certainly doesn't ...
Several Questions12/2/2010
  Q: I was wondering if I could get you to answer a series of questions for me, they all revolve around ...
  A: I have no idea why or how you would pay me to answer these, but the first one is ridiculously ...
High School Science Fair12/1/2010
  Q: I am currently a freshman at high school, and was looking for a science fair project that I could do ...
  A: Parallel universes are, of course, out. Seriously, what equipment can you get and where would you ...
self-force11/30/2010
  Q: This is with regard to the self-force or radiation reaction force in electrodynamics. There is ...
  A: Of COURSE they're significant, otherwise they wouldn't be considered. Shortcomings to science? ...
High School Science Fair11/29/2010
  Q: I am currently a freshman at high school, and was looking for a science fair project that I could do ...
  A: You're a freshman, that means you can handle a project, but not what you will be able to handle as a ...
magnetic properties11/29/2010
  Q: if i had a non metallic tube that on the exterior had 1/4 arc magnets evenly spaced along the outer ...
  A: Eddy currents would create forces resisting its motion. As for your second question, it would ...
guass law11/26/2010
  Q: why is electric field everywhere ON the surface of a guassian surface ZERO?? ANSWER: In general, ...
  A: Because the field is zero, if the cavity was ellipsoidal, then there's a non-spherical component to ...
question about heat11/25/2010
  Q: when water boils, and turns to steam, why does the heat always go up? My guess is that the water ...
  A: While water vapor is slightly less dense than air, it's also much *hotter* than air and therefore a ...
Damage done to a body when it falls11/23/2010
  Q: a science teacher that specializes in biology so this is a little out of my realm of expertise. I ...
  A: This is incredibly complex physics depending on the angles of impacts (meaning the entire detailed ...
magnitude and direction11/17/2010
  Q: how do i find an answer of magnitude and direction if my question doesn't involve direction? ex. ...
  A: The question says "across." That means perpendicular to the direction of flow. So use the ...
Air and water dynamics - air lift pump princple underwater11/15/2010
  Q: I'm interested in understanding the dynamics between air and water in the underwater environment. ...
  A: made it much clearer. It should work just fine, as long as the bottom is open for the water to ...
phase and group velocity11/14/2010
  Q: What does the following paragraph mean? As you toss a rock into a pond. If you concentrate on a ...
  A: To be any more specific about the interference of waves in your specific problem, I think I'd need ...
phase and group velocity11/13/2010
  Q: What does the following paragraph mean? As you toss a rock into a pond. If you concentrate on a ...
  A: I don't know who said that, but it basically means that the front waves are fading and the group of ...
Quantum Mechanics11/13/2010
  Q: Why v(quantum)= hk/2m*2PI where k^2=2mE/(h-bar)^2 Why not just v=hk/m*2PI ??
  A: You just basically asked me why does 1+2=3 where 1+1=2, why not just 1+2=3? You quoted the same ...
radio wave help11/13/2010
  Q: I am just starting out in shortwave and went to wikapedia.com for help. I know when the Ionosphere ...
  A: You got two answers that agree (if you thought they disagreed, re-read your own question), and I ...
Casuality11/12/2010
  Q: I am an Italian student of Arts who is beginning to self-teach something of natural and exact ...
  A: I think you mean "random" and not "casual." The forces causing their movements are well-understood ...
Dielectric material11/8/2010
  Q: I am trying to find a commonly available dielectric material that is transparent (or semi ...
  A: For a nuclear battery, you're better off using a conventional design with phosphors or scintillator ...
guass law11/6/2010
  Q: why is electric field everywhere ON the surface of a guassian surface ZERO?? ANSWER: In general, ...
  A: No, in a truly electrostatic situation, all surfaces in a conductor are equipotential surfaces. If ...
mass11/4/2010
  Q: i am a medical student and i just wonder if the word mass in medicine interfere with mass in ...
  A: This question makes very little sense, because of the lack of proper grammar and punctuation. Mass ...
physics10/29/2010
  Q: Work=force*displacement,when an athlete runs along a circular track his displacement finally becomes ...
  A: Huge amounts of chemical energy are required to cause the muscle fibers to contract and make the ...
movement sensor10/28/2010
  Q: I have a motion sensore baby monitor, (not a visual one that you see/hear the baby) this detects ...
  A: Perfectly OK. No scientific study has conclusively linked even heavy cell phone use to cancer, no ...
physics10/28/2010
  Q: Regarding trains Is the one pulling from front or the one pushing from the rear doing more work-or ...
  A: It's really about the same. A train is so long that torque and friction play very little role in ...
help on project10/26/2010
  Q: my question is about my project on sound ,we have to create a working model of the project and also ...
  A: You can use a ripple tank, but probably everyone will do that. Why don't you get a kitchen baking ...
physics10/26/2010
  Q: rex shot an arrow into the air and it fell to earth he shot it at an angle of 38 degress and a speed ...
  A: The fletchings on an arrow are designed to keep it flying in a more straight line than a standard ...
physics10/26/2010
  Q: good day sir,i am an undergraduate of physics electronics in a Nigerian university presently in my ...
  A: Well, you mention electronics. That's not really my specialty, but you could do circuit design for ...
physics10/26/2010
  Q: i read about time machine , i take interest in physics , but i think that making time machine is ...
  A: No one knows, because no one has come up with a good scheme for a time machine...or we would've ...
3D Visual Information10/24/2010
  Q: I know this might not strictly be a physics question, but I had a photography idea in mind I wanted ...
  A: I'm not sure what you mean by the word "defusion," but the whole point of strapping two cameras ...
3D Visual Information10/24/2010
  Q: I know this might not strictly be a physics question, but I had a photography idea in mind I wanted ...
  A: The type of "advice" you're looking for isn't like legal "advice," where you can hire someone cheap ...
radioactivity10/23/2010
  Q: do element emit all radiations means alpha, beta and gamma at same time or only one type of emission ...
  A: No, the uranium itself pretty much emits just alpha particles. You can see the modes of decay by ...
What happens?10/23/2010
  Q: What happens when you die?
  A: This is more of a chemistry question, since the physics of what happens when you die is that ...
radioactivity10/22/2010
  Q: do element emit all radiations means alpha, beta and gamma at same time or only one type of emission ...
  A: Isotopes, not elements. For example, oxygen 15 is too light to emit alpha particles, but will ...
3D Visual Information10/22/2010
  Q: I know this might not strictly be a physics question, but I had a photography idea in mind I wanted ...
  A: Actually, my older brother is an expert in this matter. However, unless you have the ability to ...
Superposition10/22/2010
  Q: According to quantum mechanics a physical system is in a superposition until it interacts with ...
  A: Basically, superposition just means "it adds up." That means the same thing in electrostatics as it ...
ask questions10/21/2010
  Q: an elevator and its load have a total mass of 800kg. find the tension,T in the supporting cable when ...
  A: OK, people apparently don't read my "I don't answer homework questions part," and that's how they ...
Superposition10/21/2010
  Q: According to quantum mechanics a physical system is in a superposition until it interacts with ...
  A: No, not positions. It means that vector quantities add up, that they're superimposed on one ...
Physics hw help ;]10/20/2010
  Q: A ball is thrown upward. What is its maximum height? Its initial vertical speed is 10.2 m/s and the ...
  A: The acceleration of gravity is positive? Then it'll keep shooting up at an accelerating rate until ...
electromagnetic induction10/20/2010
  Q: i know that a electric current creates a magnetic field and vice versa but why? what's the science ...
  A: Not quite. Currents create static magnetic fields. Changing magnetic fields create electric ...
Air VS Water10/19/2010
  Q: DivingIt is a known fact that air doesn't go easily underwater. I'm trying to figure out if there ...
  A: As little energy as possible? Yes, probably there's some kind of way to do it without using a ...
Water Draining out of Washer10/19/2010
  Q: We had a clog....and thought we removed it....now we still have a slow drain....I am thinking that ...
  A: You probably have less flow out of your hose than you do out of your laundry machine. Or just a ...
physics10/18/2010
  Q: what general relationship between an ability to conduct electricity and an ability to conduct heat, ...
  A: See here for detail, especially the bottom of the page about metals: ...
ringing sound in our house10/16/2010
  Q: "Our home is 5 years old. Insulated concrete home with radiant (plastic tubes)heat in concrete ...
  A: Very difficult problem, due to the resonances and interference effects of high-frequency sound. ...
electromagnetism10/15/2010
  Q: My son did a science fair experiment making an electromagnet using different gauges of wire. The ...
  A: The thinner wire can wrap in more turns/inch than the thicker wire, which is the primary determiner ...
newtons laws10/13/2010
  Q: if a 50g carton is sliding at 4 m/s across an icy surface, what force is necessary to stop the ...
  A: 50g is really tiny, can you even call that a carton? You probably read the problem that said 50 kg, ...
Stable particles10/12/2010
  Q: Do the atoms that form glucose or cellulose(carbon atom,oxygen atom,etc) consider as stable ...
  A: That's exactly what I typed. 14C occurs at about 1 part per trillion, so the rest of the carbon ...
energy storage10/11/2010
  Q: how is energy stored in atoms? how is electrical potential energy stored is there a possible way to ...
  A: Energy isn't usually stored in atoms, it's stored in the form of molecules with the potential to ...
science fair paper10/6/2010
  Q: hey i have to write a three page paper on my science fair project. the project is on "if i drop an ...
  A: Research? I would start by wrapping the egg in different protective packages and actually dropping ...
Physics (I think)10/4/2010
  Q: My fourth grade students and I were discussing how far crickets can jump. We discussed that if a 6 ...
  A: Yes, that would definitely break your legs. Bone strength varies widely person-to-person based on ...
What sort of limits do the laws of physics put on the strength of materials?10/4/2010
  Q: I may have asked a similar question before/elsewhere, but I couldn't find any conclusive results on ...
  A: The future is wide open for several reasons. First, we don't know what makes up 80% of the ...
Electroscope10/4/2010
  Q: i have this physics project where i have to construct an electroscope. i haven't been given any ...
  A: The website looks good. Did you use a single piece of foil bent in half or two actual separate ...
work10/3/2010
  Q: when golfing, i pull my bag on a cart and my friend carries his. assuming we hit in exactly the ...
  A: While technically neither of you do any work if you're not moving the bags against the force of ...
displacement9/30/2010
  Q: You are rushing to the train station to catch your morning commute. The train leaves the train ...
  A: a) You don't. Do you know how fast 8.5 m/s is? There's no way you can run the 100m dash in 11.7 ...
physics9/29/2010
  Q: about the archimedes principle...i want to ask the different between when an object is floating the ...
  A: This question is phrased completely improperly. Archimedes' principle is simple and ...
Mirage question9/22/2010
  Q: Is the waviness above the toaster a mirage? Is it right to say that a mirage can only be seen from ...
  A: This is no longer a physics question, it's an English question. Therefore, I shall refer to my ...
Fluid Dynamics9/20/2010
  Q: I'm a student studying some physics. Now, we were given a project to make a boat propelled by a ...
  A: Ducting the fan in the manner you're talking isn't really going to gain you anything aside from some ...
Fluid Dynamics9/19/2010
  Q: I'm a student studying some physics. Now, we were given a project to make a boat propelled by a ...
  A: OK, your question is tricky. It would create a shaft of decreasing diameter in water, also, of ...
Can a mirage happen in a car?9/19/2010
  Q: When I park my car in a parking lot just below the hot sun for an hour, the inside of the car will ...
  A: Visual distortion is just that, bent light as you look through something that distorts the image of ...
Can a mirage happen in a car?9/18/2010
  Q: When I park my car in a parking lot just below the hot sun for an hour, the inside of the car will ...
  A: You might see some waviness, like you do above a toaster, but it's unlikely unless you open the ...
Ramps9/17/2010
  Q: Why is it that when a ramp becomes steeper, and an object is placed on that ramp, say a toy car, for ...
  A: The force is always the same, gravity. The component of force along the ramp is what changes. As ...
melting of ice9/17/2010
  Q: sir please answer my question the latent heat of fusion of ice is 336J/g. Now when we supply heat to ...
  A: Molecules in thermal equilibrium (which is maintained because you're heating slowly) share energy ...
Light9/15/2010
  Q: What happens to the light when you turn off the lights and why does it go dark instantly?
  A: Light is constantly being absorbed by surfaces, which is why we have to keep the lights on to ...
Where does a mirage happens?9/15/2010
  Q: Is it right to say that a mirage only happens in large open places such as desert and highway? Does ...
  A: Right at the surface of a parking lot is reeeally hot because of the Sun. That makes a huge ...
Air resistance and pressure9/13/2010
  Q: I am a meteorologist working on a research project. Are you aware of any mathematical relation ...
  A: Are you really a meteorologist? You should probably consult this page, where viscosity is largely a ...
Whole Body Vibration Platforms9/7/2010
  Q: I am researching the purchase of a Whole Body Vibration machine for my mother who has osteoporosis. ...
  A: No, if the two were truly identical in amplitude settings and frequency. In the real world, the ...
Water Pressure9/5/2010
  Q: How is water pressure measured? Like what units? The size of the opening of where the water comes ...
  A: Not energy, power. Just about anything can be built with the proper engineering. You'd need to ...
Water Pressure9/5/2010
  Q: How is water pressure measured? Like what units? The size of the opening of where the water comes ...
  A: It's measured with a mechanical pressure gauge, like air pressure is. Pressure is in force/area ...
Physics Project9/4/2010
  Q: I'm a senior student right now. We need to make a project in a week, and until now, i still don't ...
  A: There aren't many good projects involving gravity which you can actually do without advanced ...
Gen physics8/29/2010
  Q: 1)What is the use of a solenoid in daily life? 2)I can't understand why we need to define magnetic ...
  A: Solenoids usually operate switches and valves. They're in your dishwasher and car blinker. Review ...
Question about electricity8/29/2010
  Q: I was wondering; have you ever read WHY electricity goes - if you grab a wire - down through your ...
  A: There's a finite resistance in the wire, and an electric field across it. It doesn't matter whether ...
AC8/28/2010
  Q: SIr few questions on AC generator and altrnating current. 1) In all textbooks i have seen it is ...
  A: You get an alternating EMF from a generator, so you'll get the same pattern no matter what position ...
Physics8/27/2010
  Q: Who will get wet more in rain? The one who slowly walking or the one who is running faster? ANSWER: ...
  A: The person moving faster will run into droplets that would fall in front of him between his head and ...
Physics8/26/2010
  Q: Who will get wet more in rain? The one who slowly walking or the one who is running faster?
  A: Over the same amount of time, the person who is running will actually get slightly more wet. ...
Creating electricity8/23/2010
  Q: All most (if not all) way of creating electricity use some sort of input, i.e. hydroelectric power ...
  A: Current formed? That depends on how the magnet is spun relative to the wire. But the energy input ...
Dents and scrapes8/23/2010
  Q: A lady backed into me at a grocery store parking lot. I was stationary and blowing my horn to try to ...
  A: There shouldn't be enough information in a photo of just damage to her car alone to determine which ...
How FTL works in Frank Herbert's "Dune"8/22/2010
  Q: and thanks for your willingness to answer questions. Some secondary sources, such as the book in ...
  A: OK, I read though all this and it's a bunch of gobbldygook. None of it makes sense from a physics ...
fluid mechanics8/20/2010
  Q: in a infinite tube block falls and waterflows opposite to it if vel of water is v1 block goes to h1 ...
  A: What you describe isn't what would happen. There must be some kind of shape to your tube. If it's ...
Capacitors8/20/2010
  Q: We know that inductor resists any instantaneous change in current and capacitor resists any ...
  A: There's no such thing as saturated. That depends on material properties and geometry of the ...
master8/19/2010
  Q: i am student in a 3rd year physics and as i am going to finish my bachelors i want to ask if i can ...
  A: It would help going into any of those fields if your written English was more precise, firstly. Of ...
Sci-Fi related Questions Focusing on Rifts/Parallel Universes8/19/2010
  Q: Hey Steve, Not sure if this is the right place, but it's hard to find a Parallel Universe ...
  A: Well, there's certainly nothing practical you can point to for this. You're going to have to make ...
ocean pressure question8/16/2010
  Q: Nelson, I was thinking that the pressure at the bottom of the ocean is huge. What would happen if I ...
  A: No, the fluid pressure in the column in the pipe would maintain the pressure. Try it with a ...
heating ice8/16/2010
  Q: I look forward to your thoughts. Damien
  A: Not really. You can see from the phase diagram of water here: ...
clarify science question8/13/2010
  Q: Can you imagine what would happen to lives on Earth if water did not expand when freezing? Give ...
  A: Well, iceburgs would sink, so the Titanic would've never happened, but they'd be a danger to ...
Codified Universe Cosmology8/4/2010
  Q: Could the hidden variables interpretation of quantum mechanics be consistent with a codified ...
  A: The hidden variable theory of quantum mechanics have largely been discredited by experiments which ...
Red Lights7/29/2010
  Q: Earlier in the week I was taking a long drive the open road at night. The roads don't have any ...
  A: Red filters would diminish car headlight brightness and efficiency. Also, while red light won't ...
Golf/Swing/Spin/Flight7/28/2010
  Q: Aloha Steve from Maui Hawaii, We are having a debate on the pure science behind a question of how ...
  A: Your assumption starts out wrong, clubs are angled (as you know). They hit at an angle, producing ...
Solar plant in Sahara7/26/2010
  Q: I know there are talks of making solar power plant in Sahara and that if only 1% of Sahara is ...
  A: Solar thermal is a better way to go, yes, but as usual with these companies their estimates are ...
Solar plant in Sahara7/25/2010
  Q: I know there are talks of making solar power plant in Sahara and that if only 1% of Sahara is ...
  A: Desert storms would kill it, the Sun doesn't always shine in the Sahara, and I don't know where you ...
Observation/Superposition7/21/2010
  Q: I studied physics( a while ago) and came across shrodinger's cat.I followed up finding more ...
  A: You have to be careful what you mean by "observation." The word observation, in physics, does not ...
physics7/18/2010
  Q: please give me idea to make a working model on any topic of physics for class 11th (CBSE)
  A: I'm really not sure what you mean. How to make a working model? Experiment on something like a ...
Water flow calculation7/14/2010
  Q: Could you please help me with the following - water under pressure (V)is being pumped into a ...
  A: OK, not enough information. Is the pressure V1 at the lower end, the middle, or the top? You just ...
force7/13/2010
  Q: I was wondering if there was a three car (all rear-end) accident would the force from the initial ...
  A: It's not nearly that simple, and don't trust anyone who says it is. There are crush zones, you ...
Bee on a train!7/12/2010
  Q: How does a bee (or any flying creature)fly on a train, a car, a plane etc? If it's not in physical ...
  A: You're in a state of motion with the plane when you jump on it. Newton's first law of motion states ...
wind affecting running times7/11/2010
  Q: Since I see you have some expertise in trying to gage wind to running as a sprinter I have this ...
  A: Well, on a track the wind would help you on some legs and hurt you on others but even out if you're ...
rainbow7/8/2010
  Q: sir this is a question regarding rainbow I know how a rainbow is formed due to total internal ...
  A: Rainbows do vary in shape, but due to the uniformity of the mist you need to form one and the ...
One-way Plastic?7/8/2010
  Q: Are you aware of any type of one-way plastic that will let light come in one way, but not the other? ...
  A: Not really. The principle of a one-way mirror involves more light on one side than the other, so ...
Time, Distance and Speed6/24/2010
  Q: Firstly, I am not requesting you to solve a text book problem. In fact, I could not really ...
  A: The problem is that you're trying to visualize the whole physics problem at once. Common mistake. ...
Boiling Ice6/23/2010
  Q: hi i was wondering what happens to ice when you boil it?
  A: You either mean you're trying to heat the ice by dropping it into boiling water? The stress will ...
physics6/23/2010
  Q: I have a question to you about X-ray and ultrasound. Is x-ray can penetrate more inside the human ...
  A: Well, they're completely different. It depends on the frequency. If you mean actually going all ...
falling speed6/23/2010
  Q: i recently fell 20ft out of a tree,and i weigh 202lbs.can you tell me appox.how fast i was going ...
  A: How much you weigh doesn't matter, gravity pulls on you harder but you've got more inertial mass to ...
temporal mechanics6/21/2010
  Q: Is infinitely small the same size as infinitely large ? ANSWER: No. Small is not equal to large, ...
  A: You can disagree with me all you want, but until you can adequately define infinity in a proper way ...
temporal mechanics6/21/2010
  Q: Is infinitely small the same size as infinitely large ?
  A: No. Small is not equal to large, they have meaning in our comprehension of language and ...
N-machine6/20/2010
  Q: Bruce Delpalma of MIT patented a homo-polar generator that didn't suffer the effects of back emf.Is ...
  A: It's real technology, based on eddy-currents in the disc, and it was invented waaay back in 1831 by ...
DG set6/19/2010
  Q: How do we calculate carbon content in 1kva DG set? I have gone through many websites and all they do ...
  A: First, it doesn't have carbon content. It will produce carbon dioxide at a certain rate while in ...
gallons of oil - 55psi6/17/2010
  Q: how many gallons per minute of oil through a 4 ft 1/2 inch diameter line equals 55psi? Help!...I ...
  A: I answered your second question on this topic already, 41 gallons/minute. See below:Kendall series ...
Leg Sled physics6/16/2010
  Q: I've noticed that people in the gym can load way more weight on the leg sled machine than they could ...
  A: I answered this yesterday, but allexperts appears to have eaten my response. The sin(45)=0.70. ...
maximun puck speed point6/14/2010
  Q: Hockey players say it is better to block the shot closer to shooter than farther away. Does this ...
  A: Maximum speed happens right after the puck leaves the stick. However, you say that it's "better" to ...
vacuum technology6/14/2010
  Q: I was hoping you could help my brother and I with an argument we have regarding vacuum technology. ...
  A: A longer hose has a lower conductance, which is more important in vacuum systems than "suction." ...
What The Bleep Do We Know6/13/2010
  Q: The film that I specified suggests various pseudoscientific and irrational things, including that ...
  A: This film is one of the worst films ever made. The best physics expert they could come up with in ...
Radium clock6/13/2010
  Q: I am very interested in building a "radium Clock". Such as the one at the link below. ...
  A: 1) Sure, its half-life is even longer. You can find 241Am in many models of smoke detectors, it's ...
Rotating wheel.6/12/2010
  Q: Nelson. I wish to know how wheel rotation works. Suppose If I rotate a wheel (with center point 'O' ...
  A: Weeeelll, this sounds homeworkish, but not directly. Just realize that angular velocity is just ...
Gravity6/8/2010
  Q: The equation for height of a mass is y=-1/2gt^2+v.t+y. when we suppose the gravity acceleration ...
  A: If the change in height is small compared to the distance from the center of the Earth, you can show ...
Lost World Jurassic Park6/2/2010
  Q: In a scene in Lost World: Jurassic Park, the girl Kelly kicks a raptor out a window. Given the ...
  A: She should've bounced back more, but the velociraptor can't ignore physics. As strong as they were, ...
Physics6/1/2010
  Q: Nelson, My question is about special relativity, regarding time dilation at speeds close to the ...
  A: I'm not sure I understand what a "c-ship" is, so I'll assume you mean some form of spacecraft. You ...
Can energy be created or destroyed?6/1/2010
  Q: I have heard of quantum particles that do exist in a non-existent state they switch 'off' and back ...
  A: No, it can only be borrowed for a time allowed by the uncertainty principle. And I'm not sure what ...
water5/30/2010
  Q: Water has a boiling point of 100 degrees Celsius. When you pour water on a glass surface or any ...
  A: Water has a finite vapor pressure at any temperature. Even in your freezer, ice cubes will ...
This has been bothering me5/28/2010
  Q: How could a cat respond, and react, to a human's hallucination? How could I be at the speed of 40 ...
  A: A cat? I'm not sure what you mean by how a cat would react in the context of the rest of this ...
Physics Learning5/24/2010
  Q: I'm a student and i need some advice regarding learning physics. I have a lot of difficulty doing ...
  A: Actually, you can tackle it either way. You can either read the theory and do the problems to learn ...
Physics Learning5/23/2010
  Q: I'm a student and i need some advice regarding learning physics. I have a lot of difficulty doing ...
  A: Yes, what you need to a particular type of practice which will give you the confidence to solve ...
quantum physics5/23/2010
  Q: A new age person told me that everything has light in it including all cells and atoms. She said ...
  A: Everything has electromagnetic forces, but not what you would perceive as "light" inside it. ...
hello5/22/2010
  Q: Are you sure that newtron is chargless? ANSWER: Yes. Interferometry experiments prove it. ...
  A: Well, the question here is what's kinda backwards. X ray and gamma ray are names we give to photons ...
Conservation of energy5/22/2010
  Q: As the altitude increases, do the velocity of air increase or not? If increases then how the energy ...
  A: Conservation of energy is ever-present and always important...and has very little to do with the ...
general physics5/20/2010
  Q: this is varma and my question is " why does a motorbike appear to weigh less when in motion than ...
  A: It does not weigh less or appear to weigh less. Weight is the vertical force of gravity, if you ...
Electricity5/20/2010
  Q: I'm a 12th grade student.I'm confused a lot about electricity and it's hard to imagine the flow of ...
  A: There isn't a direct one, because there's not "positive water" and "negative water." I have to ...
Doubt5/20/2010
  Q: A person is sitting in a car that travels with constant velocity. He throws a ball verticall ...
  A: It was moving at the same horizontal speed as the car when he threw it, he didn't throw it forwards ...
Very stange occurance.5/19/2010
  Q: One night playing light tag with my daughter, I noticed a stange phenomenon. The living room is ...
  A: Well, I tried it just now and got no similar effect. Where the light beams overlapped, there was a ...
Wind force5/19/2010
  Q: Why in very strong winds the roof can be lifted easily from a house without causing much damage on ...
  A: It depends on the angle the wind hits the house. Usually walls are strong to support the roof and ...
News reports on physics (for the layman)5/18/2010
  Q: I actually have two questions. 1. I read recently online that Stephen Hawking now believes that ...
  A: 1) Hadn't read the popular interview, so I went and looked it up. Check out the telling part of the ...
Electricity5/18/2010
  Q: I'm a 12th grade student.I'm confused a lot about electricity and it's hard to imagine the flow of ...
  A: I'm not particularly fond of the "shotgun" question, try and limit questions to one or two at a ...
Exactly what IS "Physics"?5/18/2010
  Q: HMMmm... As I re-read this, it seems to have the air of a rebuke about it—but trust me, it isn't ...
  A: As a word of caution on combing through my answers and interpreting me telling people that they need ...
LHC5/16/2010
  Q: In various media surrounding the LHC, there are claims that the particles attain a speed that is ...
  A: Ummm...no, this is not "just theoretical." If it were, they wouldn't be able to accelerate them to ...
Black body radiation law5/16/2010
  Q: Hope you remember me... I am here with a question after a long gap... I have few doubts in ...
  A: Reverse-order answer... 3) It does depend on the type of material. Google search the word ...
atoms5/13/2010
  Q: Hey. For science, i am studying atomic model history and i so I was wondering if you could suggest ...
  A: Ummm...I don't know what bad things we've learned, just the science that has led to good things. ...
Heating air5/11/2010
  Q: i have a question about air heating. In a instalation we are sucking air that needs to be heated. ...
  A: Sure. Multiply the heat capacity of air by the mass (1.2 kg/m^3 at 3 cubic meters per minute and 60 ...
Optics (shadows)5/10/2010
  Q: As seen in http://www.youtube.com/watch?v=KEfiUHi6SXI (between 2:40 and 3:10 of the video of the red ...
  A: It's kinda tricky, but I see it. It appears to be an optical illusion caused by polarization and ...
electricity=heat5/10/2010
  Q: how do you basically create heat out of electricity?i mean how does heating elements basically work? ...
  A: In very basic terms, electrons scatter off atoms and impurities as they are travel through a ...
Parallel universes5/10/2010
  Q: Is the concept of parallel universes proven? Are there really infinite number if universes where ...
  A: The idea of parallel universes is, at the present time, just an idea. No credible scientists would ...
.............................5/9/2010
  Q: plzz diffrentiate random error and systematic errorin the measurement of any physical quantity.
  A: Systematic errors are those which always occur in a measurement because of some fundamental error in ...
q factor5/7/2010
  Q: i have a problem about RCL parallel circuit . when we have a RCl circuit with applied sinsusoid ...
  A: You don't necessarily need to prove it, just use and understand it. Unless this is homework, which ...
egg has to survive a fall built in a toothpick and glue thing5/4/2010
  Q: I was wondering if there is a easy way to make an egg survive a fall from about a 2 story height ...
  A: You need angled crush space, as much as possible, beneath your egg. Also, a shape which won't turn ...
Neutrons5/4/2010
  Q: Is there any configuration of multiple neutrons that is stable without any protons being present? ...
  A: There is, but it's a big one. A neutron star is stable. It requires enough neutrons to allow ...
historical earth science5/3/2010
  Q: Has the quantity of water in liquid, solid and gaseous forms combined ever changed since the ...
  A: It's believed that it's possible Earth's water may have come primarily from comet bombardment in its ...
Magnets5/3/2010
  Q: I believe there are materials out there that are natural magnets? If so, do they ever lose their ...
  A: Lodestone is a natural iron magnetic material, quite strong. It would take an extraordinarily long ...
physics5/3/2010
  Q: In what ways can scientists test for the presence of each of the different components of the ...
  A: Well, this sounds homework-ish, but kinda general, so I'll give you a general answer. If you're ...
mixture temp5/2/2010
  Q: can u please tell me any formula 2 find the temperatre of mixture when 1) ice and water are mixed 2) ...
  A: There's not a single formula, you just balance the heat out of the hot objects with the heat into ...
Egg Catcher5/1/2010
  Q: I have to design an egg catcher out of 10 sheets of 81/2 by 11 inch typing paper and an arm's length ...
  A: I'd make sure you made something that would definitely stay vertical as it dropped, covered as much ...
lu4/29/2010
  Q: Are you sure electron negative charge? Are you sure electron revolved around the nucleus? ANSWER: ...
  A: For every electron in an atom, there is a proton with a positive charge. Atoms are electrically ...
lu4/28/2010
  Q: Are you sure electron negative charge? Are you sure electron revolved around the nucleus?
  A: The sign of the electron charge is negative by convention, but it's opposite to the sign of a proton ...
Physical meaning of torque4/27/2010
  Q: Oh I'm damn confused with the physical meaning of torque.Please help me. What does it 'physically' ...
  A: The direction of the torque comes from the right hand rule, which is a mathematical convention based ...
color subtraction4/22/2010
  Q: If I wanted to have one color of light on a solar panel I was thinking of using a colored filter. ...
  A: No, that's not how color transparencies work. If you shine light on or through a red object like a ...
compton effect4/21/2010
  Q: when any kind of electromagnetic radiation is incident on a metallic target the photons are ...
  A: Ummm...no, the physics you state here is all wrong. X-rays get partly absorbed and partly scattered ...
3.7v 700 mAh battery. what does it mean?4/21/2010
  Q: I saw an answer to another question that explained the 700mAh part. How does the 3.7v relate to the ...
  A: They're not related. However, when multiplied, they give the total amount of energy stored by the ...
If earth is rotating, why do we need airliner to travel?4/20/2010
  Q: My question is earth rotates about its own axis in approx 24 hours. So, if we want to go from India ...
  A: The air rotates with the Earth. If you're standing on the equator, you're moving around in a circle ...
velocity of sound4/20/2010
  Q: velocity of sound is more in H2 than in O2, but velocity or sound is more is more denser medium..(as ...
  A: Molecular speeds. You're talking about media with different phases, like solids and liquids, which ...
Electric potential4/19/2010
  Q: Sir I've had my first class of electricity today.So my q might seem a little stupid. 1)In a charging ...
  A: 1) Not necessarily. Based on the triboelectric scale, the neutral body could potentially actually ...
Physics of blimps4/18/2010
  Q: What mathematics/sciences are used to determine the size and shape of balloons to allow lift, and ...
  A: Buoyant force. Air is 1.2 kg/m^3 at room temperature, hot air and other types of balloons lower ...
u-236 in nuclear fission reaction4/13/2010
  Q: I note that u-235, the most fissile kind of uranium, in a fission chain reaction, absorbs a neutron, ...
  A: U236 in its ground state has an alpha-decay half life like what you mention, but with the added ...
Is science self contradictory?4/8/2010
  Q: I find the following article "So, do we really respond to a thing? Don't we respond' only the ...
  A: You're not accepting a scientific account, you're accepting someone's account of science. That's ...
Relative size of an object4/8/2010
  Q: I am curious about the smallest size of anything that humans can comprehend with our senses. I read ...
  A: I'm not a string theorist, so perhaps I'm not the person to ask this exact question. However the ...
Popping and Floating4/7/2010
  Q: and I have one more thought: Bubbles can easily pop, but not all the time. I've experienced a time ...
  A: The liquid material in bubbles is affected by wind and gravity, too. It's not uniform. That's why ...
is there a difference?4/6/2010
  Q: There is a bridge that connects the cities Ocean Springs & Biloxi. It is 1.75 miles long. Built ...
  A: From a standpoint of simple physics, no. You'd have to have shifting headwinds or something. ...
physics and bubbles4/6/2010
  Q: How do bubbles form? Why do they pop, and tell me about the surface tension, please.
  A: A bubble is generally a surfactant layer with water. A surfactant (usually some kind of soap) is a ...
monment of inertia , radar4/5/2010
  Q: sir (1) Two sheres of copper and lead have same mass.It is found that the lead spere can be rotated ...
  A: The lead sphere will be smaller, giving it a lower moment of inertia (rotational equivalent of ...
accident probability of vehicles of different height4/4/2010
  Q: Could you please explain why double Decker buses accident much than ordinary buses....?? the ...
  A: Probability isn't easily derived in this way, however, it is obvious that that torque ("twisting ...
p3/27/2010
  Q: On youtube.com there are a few realistic examples of people using telekineses. Do you think those ...
  A: No, I don't think it's real. I'm a physicist, the notion of their thoughts moving objects doesn't ...
physics3/26/2010
  Q: ok... I'm doing this project for science class on balloon powered cars. The testable question is how ...
  A: Your hypothesis is your guess for what will happen when you include features in the design. That's ...
follow up : alpha emitters - uranium, plutonium3/26/2010
  Q: i have read up on the production of 99Mo for medical use. The reference is ...
  A: The picture I mention below didn't attach. See here: ...
velocity...3/25/2010
  Q: if you dropped a stainless steel piece of cutlery like a fork or a knife (not like a super shard ...
  A: It's unlikely. The flat shape and any wind make it most likely that they would tumble as they fell, ...
argon gas3/22/2010
  Q: I am a plumbing and fire protection engineer getting into laboratory work. I have done medical gas ...
  A: This is a little outside my area of expertise, you need an engineer trained in these types of ...
What does it mean if the world is a hologram?3/21/2010
  Q: I read from a online article, that our world may be a Hologram, I got some question about it ...
  A: It implies that the universe has holographic properties, yes. It implies that what we perceive is ...
What does it mean if the world is a hologram?3/17/2010
  Q: I read from a online article, that our world may be a Hologram, I got some question about it ...
  A: I think it's a thin argument, and most physicists seem to agree. The idea is that distributed ...
Corn Syrup3/16/2010
  Q: I was talking to my friend the other day, and he said that if I put corn syrup in my mouth and hold ...
  A: I think you'll end up with a sticky hand. I'd try blowing the corn syrup first and see if you can ...
Thermal Conductivity3/14/2010
  Q: i have a question about my science fair project. i am testing the amount of time it takes to melt a ...
  A: You need to make sure that the copper isn't conducting heat to the brick itself. Put a piece of ...
Follow up on aggregation of plutonium dioxide3/14/2010
  Q: I just put this as a private question because i think this is too indepth to be of use to anyone at ...
  A: OK, this is really long. If you can break future questions into smaller bits it's easier to find a ...
What does it mean if the world is a hologram?3/14/2010
  Q: I read from a online article, that our world may be a Hologram, I got some question about it ...
  A: First, check with other sources than newscientist.com, half of what I see in there is highly ...
Thermal Conductivity3/13/2010
  Q: i have a question about my science fair project. i am testing the amount of time it takes to melt a ...
  A: Well, it depends on several factors. How are you heating the bottom of the surface? How thick is ...
aggregation of plutonium dioxide/plutonium in physisorption scenario3/12/2010
  Q: Really hope you can help as i really need it. you see, my orthopedic recommended me and i did a ...
  A: I'm familiar with the various processes used for production of this radioisotope, so you probably ...
forces3/12/2010
  Q: what type of forces act on moving spear with no external contact.center as spear center moving with ...
  A: I just told you, you cannot decrease the force of gravitation by moving an object with higher speed ...
Soundproofing3/10/2010
  Q: I live in a small long room in a house. How would I go about reducing sounds leaving the room, ...
  A: Really soundproofing a room is reputed to take a lot of work. I have no idea about your spray-on ...
Soundproofing3/10/2010
  Q: I live in a small long room in a house. How would I go about reducing sounds leaving the room, ...
  A: I really still don't have a good idea of the geometry you're talking about here. What walls are you ...
Soundproofing3/9/2010
  Q: I live in a small long room in a house. How would I go about reducing sounds leaving the room, ...
  A: If you place objects in an irregular pattern, the noise will have a tendency to randomly negatively ...
momentum explanation for blind student2/22/2010
  Q: Steve. I am trying to explain to a blind student why a small car can have the same momentum as a ...
  A: Perhaps a demonstration would help. Momentum comes from Newton's Laws, which mean that in the ...
car collisions2/22/2010
  Q: if a car is turning left at a rate of 15 kms per hour and is struck in the passengers side door (at ...
  A: There's no way to know. I don't know the coefficient of friction of the car's tires with the road, ...
photocell2/21/2010
  Q: If you take a typical photocell on a pocket calculator, If you shine red light on it and then blue ...
  A: "Work function" typically refers to the photoelectric effect. If you get below a certain energy, ...
question on ripples2/21/2010
  Q: Respected sir, why the ripples in a water tank are in only circular shape? why not in any other ...
  A: You can create planar waves and waves of other shapes. It's just that waves with corner shapes tend ...
Physics2/19/2010
  Q: I am a fifth grade teacher and have an experiment where my students place a thermometer strip inside ...
  A: Temperature depends on the energy of molecules have, which is kinda like how fast they're moving. ...
physics2/18/2010
  Q: tell me why the magnetic field of earth points NS always? Is it possible for the earth,magnetic ...
  A: It turns out that's wrong. The magnetic field points S-N, not N-S and it's not perfectly aligned ...
nuclear physics2/17/2010
  Q: is there any formula for the different energy levels of a nucleus as it is in the case of atoms. ...
  A: No, there are not any such formulae. The exact form of the strong nuclear force is one of the last ...
Hot Milk2/14/2010
  Q: This is a follow-on my my previous question. Just to re-cap: If you fill a mug with hot milk, give ...
  A: OK, by tapping multiple times as the stirred liquid slows down, I get what you're getting at. I can ...
SF query2/13/2010
  Q: I once read a fascinating science fiction story about an alien diplomat("Diplomatic Immunity" by ...
  A: It's not vague or arbitrary, really, energy production and consumption drives civilization. There ...
TIRE FRICTION SCIENCE PROJECT2/13/2010
  Q: I AM IN 8TH GRADE AND AM DOING A SCIENCE PROJECT ON TIRE FRICTION. I NOTICED WHEN AN AIRPLANE LANDS ...
  A: Tire smoke from cold airplane tires is quite different than hot tire smoke. It's particles which ...
Maths / Physics2/10/2010
  Q: Is there a formula for working out how far a fire fighter can pump water. can you calculate the ...
  A: Fluid mechanics just isn't simple. You can try to estimate it from the pressure of the water and ...
Physics2/10/2010
  Q: Annular Solar eclipse occurred on 15th Jan 2010.How did it took place and when
  A: You just said when it was. It happens when the Moon passes between the Sun and the Earth, but far ...
Wave2/10/2010
  Q: Common mathematical representation of wave: Ψ_(x,t) =A cos(kx±ωt) ……………………….1 ...
  A: The physical meaning depends on the type of wave you're trying to describe. Since I don't know what ...
baseballs2/9/2010
  Q: How far would a heated baseball travel if hit off a tee?
  A: By what kind of bat, moving how fast, and with what kind of impact parameters for the baseball? At ...
Triple Point Analogy2/9/2010
  Q: I'm looking for a good analogy which would quickly and visually explain the concept of the Triple ...
  A: Well, you can choose your own crowded situation if you like, but I'd compare it to a stadium rock ...
Triple Point Analogy2/8/2010
  Q: I'm looking for a good analogy which would quickly and visually explain the concept of the Triple ...
  A: At the triple point, what students have to understand is that the molecules are still at a finite ...
MAJOR science fair help with ferrofluidic damping2/8/2010
  Q: I'm trying to design an experiment on ferrofluidic damping and how it changes with the strength of ...
  A: You may have already realized this, but do be careful with ferrofluid. It's mildly toxic and ...
Physics-optics2/7/2010
  Q: Please explain what's caustic curve and how can it be avoided by using a parabolic concave mirror.
  A: A caustic curve is the curve of light reflected from a point surface by a curved surface. ...
Hot Milk2/6/2010
  Q: this is a very basic physical observation but no-one can tell me the answer. If you hold a mug (any ...
  A: OK, so when you say "hot milk" you mean milky coffee? Coffee is an especially interesting liquid ...
Recovering from a collision2/5/2010
  Q: I think you're the right person to whom I can ask this question. If not, my apologies. How long ...
  A: I'm not quite the right person to ask this, because modeling environmental fallout is not my ...
Physics/Project In Fair2/4/2010
  Q: Nelson, I am in the 7th grade, and were doing a upcoming science fair.And my projcet is, Do white ...
  A: If it's daytime, then there's light outside. While your body heat may convect just as well through ...
Is the Wireless Power Transmission Concept of Nikola Tesla working according the principles of Electrostatic Induction ?2/4/2010
  Q: Is the Wireless Power Transmission Concept of Nikola Tesla working according the principles of ...
  A: I didn't learn anything new. The ground is a simple conductor because of its geometry and material ...
Can Light Particles contain Charges (Electron)2/4/2010
  Q: Can Light Particles contain Charges (Electrons) ? Hello Steve, How are you ? I am working on a ...
  A: I'm sorry, but this book is a work of pure fiction. He's talking about spaceships and gravity beams ...
car crash2/3/2010
  Q: Is it possible to tell from pictures of vehicles from an accident how accident happened and where ...
  A: Most of these cases are settled out of court for shockingly little money compared to how much was ...
car crash2/3/2010
  Q: Is it possible to tell from pictures of vehicles from an accident how accident happened and where ...
  A: In general no. You can put some basic physics limitations on some things, but generally photos ...
heat absorbment2/1/2010
  Q: I am in 7th grade and im doing a science fair project involving heat absorbment. My question is what ...
  A: Sure. Hard question to answer without direct data, but at least you have a question and can take ...
Physics -force of impact1/30/2010
  Q: Vehicle #1 traveling 55 MPH is hit from behind by vehicle #2 traveling 90 MPH, can you calculate the ...
  A: No, there's nowhere near enough information to answer this question. You know nothing about the ...
Trains1/30/2010
  Q: In my exam there was a question "When a train(rail)driver starts a train(diesel train) he first ...
  A: Unless there were some restoring force, like a force in the engine itself or the train was on a ...
atmospheric pressure and weight1/30/2010
  Q: Does atmospheric pressure have an effect on an object's weight? If so then am I lighter at higher ...
  A: Yes, pressure affects density, which affects buoyant forces...but at higher altitudes the air will ...
Possible Electroluminenscence?1/29/2010
  Q: You pointed out that you enjoy explaining odd observations so was hopeful you could answer my ...
  A: It's too weird even for me, if it really cuts off suddenly then it can't come from the plastic ...
Egg Drop Answer1/29/2010
  Q: Steve, I just read your answer to the egg drop question. Can you explain how gravity is causing ...
  A: Gravity exerts a force downwards. The force causes acceleration. Eventually, if you reach a high ...
Wet Towels1/28/2010
  Q: When a wet towel is flicked, it may create a cracking sound like a whip.(I suppose this is an ...
  A: Momentum. The wet towel has more mass, when you swing it you put more momentum into the whole towel ...
thermal expansion1/27/2010
  Q: A hollow steel sphere ,weighing 200kg is floating on water.A weight 10 kg is to be placed on it in ...
  A: I don't answer homework, but I'll give you a hint: The volume of the hole will expand at the same ...
physics1/26/2010
  Q: "safety boots help to protect workers throughout the word in many different types of occupations. ...
  A: Insulating shoes would protect the wearer somewhat from anything they might touch that would be ...
Physics1/25/2010
  Q: I am Marium from first year.Why light never pass through shadow?please help me,i'll be very thankful ...
  A: Light can pass through a shadow. If I have a shadow under an umbrella from the Sun, I can shine a ...
why systems tend to go wrong?1/25/2010
  Q: Sir, i need this for my understanding and research. why do systems tend to go wrong? i have ...
  A: OK, you're asking me to simplify an entire field like reliability engineering into this forum. ...
Science fair1/22/2010
  Q: I am doing a project on how high an egg can drop, and right now I am looking for some info. How does ...
  A: The height depends radically on the egg and on the surface it lands on, so I can't answer the second ...
Possible Electroluminenscence?1/22/2010
  Q: You pointed out that you enjoy explaining odd observations so was hopeful you could answer my ...
  A: Hmmm...this is a tough one. I've never heard of anything like that cycling as well. I figure you'd ...
Water and Friction1/22/2010
  Q: How is it that water can decrease friction on a surface (slipping in a wet hallway) but sometimes ...
  A: The water changes the surfaces you're talking about. It makes paper puffy and rough, increases the ...
Intensity Ratios1/22/2010
  Q: Mr. Nelson I know that this is a mathematical question of some kind. However, I am not certain if ...
  A: Ummm...see wikipedia for a better example of how to do variation in brightness (near the bottom of ...
Waves1/21/2010
  Q: How do I find the "curved" distance of a wave if I only know the straight peak to peak length ? ...
  A: Ummm...that's easy if you know the amplitude, because you can write down a form for the length of a ...
electromagnetic waves heat1/19/2010
  Q: I am doing an extracurricular engineering project - the Engineering Education Scheme England(not ...
  A: Sure, as long as people aren't near it. I mean, you could microwave the roads or use and infrared ...
Leg Muscles1/14/2010
  Q: Okay, so I would like to say sorry, but I WAS offended that you thought I was being deceptive. In ...
  A: Gravity acts into the surface, but the way you put it was as if the acceleration of gravity was in ...
radiation1/12/2010
  Q: If ozone layer is protecting us from harmful radiation then how the astronauts manage to be there ia ...
  A: You're misusing the word radiation. The ozone layer stops ultraviolet radiation, which is near ...
Leg Muscles1/11/2010
  Q: Okay, so I would like to say sorry, but I WAS offended that you thought I was being deceptive. In ...
  A: No, it's just not that simple, every runner's legs have a different stiffness and length, as well as ...
ENERGY SCIENCE1/8/2010
  Q: WHAT IS THE POTENTIAL ENERGY OF AN OBJECT KEPT AT THE SURFACE OF THE EARTH? HEIGHT h = 0 THEREFORE ...
  A: Potential energy needs a reference point. There's no absolute potential energy, only changes in ...
GROUND POTENTIAL1/7/2010
  Q: I measure a potential of a body using infinity as the reference point. Then I measure the potential ...
  A: They're not the same, the Earth has an electrical field at its surface but that's heavily attenuated ...
Electrical measurements1/6/2010
  Q: I'm an engineering student. Our teacher taught us that the range of an electrodynamometer voltmeter ...
  A: Well, it really measures current. I'm surprised it doesn't read in Amps or, if the voltage is ...
GROUND POTENTIAL1/6/2010
  Q: I measure a potential of a body using infinity as the reference point. Then I measure the potential ...
  A: Yes, it's not necessarily the same. All potential is relative to a reference point, but "ground" ...
Speed of light1/6/2010
  Q: We know that the light travels at a speed of 3,00,000 km/sec. Does the light emitted by a tube light ...
  A: All light travels at that speed, yes. The distance thing is a matter of intensity being spread out ...
volume of a gas due to water vapor1/5/2010
  Q: I am not a student. I need to know if when passed through water, if a gas will experience a volume ...
  A: Yes, water molecules occupy space and a dry gas passed through water would get molecules of water ...
entropy reversal1/4/2010
  Q: I'm wondering whether it is ever possible for the entropy of a closed system to drop. In a ...
  A: It's possible for entropy to drop, just statistically so unlikely that you never observe it ...
Liquid nitrogen12/31/2009
  Q: My name is Jonny.  I'm 14 and in a advanced 8th grade science class.  I'm making a maglev train for ...
  A: Carnot efficiency is 1-Tc/Th, which for room temperatures equals about 34%. Typically you get half ...
Electrostatistics12/31/2009
  Q: In the diagram..... http://oldfacebookrox.t35.com/fys.jpg (its working now) Had the concentric ...
  A: No, there's no written mathematical proof. By Gauss's Law, if I enclosed net charge inside a metal ...
Physics12/29/2009
  Q: 1.What is mean by horizontal accelerations and how it can be measured? 2.What is the unit of the ...
  A: Horizontal, vertical, it doesn't matter. Acceleration is acceleration. Acceleration is measured as ...
Maxwell's Equations12/28/2009
  Q: I got stuck with Maxwell's equations thinking about their in depth meaning. Most of the examples ...
  A: Maxwell's equations relate electric and magnetic fields to the position and motion of charges and to ...
Physics - focal points and lens power12/28/2009
  Q: I am trying to work through a homework question associated with a focal length, distance to object, ...
  A: I think that your textbook might have meant the object and the image units for size or position. Of ...
burning questions12/27/2009
  Q: Referring to this diagram, http://dl.dropbox.com/u/3579325/Untitled.jpg The textbooks state: Rays ...
  A: Yes, the ray diagram is an approximation which assumes an infinitely thin lens. The only time a ray ...
Optics-sprectum12/27/2009
  Q: Is it possible that an atom can radiate frequency of complementary color in hot condition of the ...
  A: No, the energy levels of atoms are fixed and determine their emissions. Also, "complementary ...
decay of matter12/27/2009
  Q: Sir, I would like to know why materials biological and non-biological decay or disintegrate over ...
  A: y a First, you must understand that your question is quite odd. Idleness? An explosive compound ...
clouds12/24/2009
  Q: Cloud is a condensed form of water. Its weight must be higher than water vapor and even the ...
  A: There are several processes involved. As droplets fall the air around them heats up so they ...
electric current12/24/2009
  Q: I'm getting confusion by understanding these two questions. 1.What is the difference between emf and ...
  A: 1) they're similar. Both have the same units, Volts. A potential difference is caused by charges, an ...
guitar string tension12/24/2009
  Q: I have occasion to change the pitch of certain strings on my guitar for different pieces that ...
  A: The local stresses of strings are really pretty extreme because of the small diameter of the ...
guitar string pitch/temperature12/23/2009
  Q: This question may or may not be related to the previous question about string tension. The 3 lowest ...
  A: Again, slightly outside my area of direct expertise, but hydrocarbons don't expand when heated like ...
Punkin chunkin12/21/2009
  Q: Has anyone heard of Punkin Chunkin in Delaware? Well we are building an air cannon to shoot the 8-10 ...
  A: Is that big enough for your pumpkin? Will the barrel explode? You should always make a smaller ...
Feather at high speeds12/21/2009
  Q: My brother and I are in a bit of an argument. He says that a feather traveling at a high rate of ...
  A: The stone/window would exert forces on the feather and the feather would exert the same (not less, ...
Radiation12/17/2009
  Q: I am developing a presentation on Radiation (both ionizing and non-ionizing) and I need a simple ...
  A: Well, you're not really going to do much better for keeping your explanation simple than the ...
Velocity of two objects in outer space12/17/2009
  Q: I have a simple question to ask you that may be a simple or complicated answer. If you have two ...
  A: No, they don't necessarily have the same mass so they won't go the same distance or reach the same ...
Science Fair Project12/16/2009
  Q: OK, i cant think of a really good science fair project. i am in 12th grade and am extremely ...
  A: OK, projects involving things like you mention are generally the province of major research ...
Torque Question follow-up12/16/2009
  Q: A two cylinder 4 stroke gas engine has 360 degree crankshaft (pistons rise and fall together) and ...
  A: The basic physics would seem to make the result the same, but the power delivery will be far more ...
Teleportation a Reality12/15/2009
  Q: I am working on a science project pertaining to technology around 20 years into the future. Since ...
  A: Be careful, an idea which "seems more realistic as each day passes" is one you're fixating on ...
Science of an Intelligent Universe12/15/2009
  Q: Greetings Mr Nelson, My work on www.ascensionq.20fr.com is religion and science based and is a ...
  A: It takes a lot longer to review work with such a large body of reading to do, and posed in such long ...
Science Fair Project12/14/2009
  Q: OK, i cant think of a really good science fair project. i am in 12th grade and am extremely ...
  A: Astrophysics directly, you're waaaay too late in science fair season to get a serious project ...
optics-magnification12/11/2009
  Q: how can an image be magnified ?, because if a real image is magnified, then no.of rays emitted by an ...
  A: It's easier to read if you turn off the caps-lock key. Your drawing is a little off, the image ...
Science of an Intelligent Universe12/11/2009
  Q: Greetings Mr Nelson, My work on www.ascensionq.20fr.com is religion and science based and is a ...
  A: I study alternative theories of physics, actually. This one is similar to theories of physics I've ...
ice skating12/10/2009
  Q: I am about to start competitive figure skating and was wondering about the friction between the ice ...
  A: What precisely were you wondering about? At best, the way it's posed right now, I could answer this ...
Projectile motion12/10/2009
  Q: "A line runs like this "For two projectiles to collide,mid-air, their relative velocities must be ...
  A: It means that you need to forget about observers on the ground and only think about looking at one ...
What would be better?12/6/2009
  Q: What in your opinion would be better suited to act as a parachute for an egg, an old rag(old, used, ...
  A: I would think a rag would be bigger and therefore a better parachute. But if you get to use more of ...
vibrations12/4/2009
  Q: Does every atom and cell in our bodies vibrate? If so, what does this mean? Would it involve ...
  A: Sound is everywhere at finite temperatures and atoms do vibrate...but the scale of atoms and the ...
speed of 40 ft fall and impact force12/3/2009
  Q: I recently had an accident will working in which my equipment failed causing me to fall from the ...
  A: I get these questions all the time, usually from people with court cases pending, and I can only ...
CLASSICAL MECHANICS12/3/2009
  Q: Sir, A long time has gone since my last question. Today,I have few doubts in classical mechanics. ...
  A: I believe, based on your problem number 3, that your book has the same misprint as mine where the j ...
Spring Scales12/3/2009
  Q: WHAT DOES THE DARK LONG LINES ON A SPRING SCALE REPRESENT? WHAT DOES THE LIGHTER, SMALLER LINES ON ...
  A: A spring scale is a simple device for measuring weight, but you'll have to be more specific about ...
Space Missions and Momentum12/2/2009
  Q: If a spaceship used momentum, shouldn't it be able to make the return trip using less fuel than the ...
  A: I'm not sure what you mean by momentum. Do you mean that the momentum of the outbound spacecraft is ...
cathode ray12/2/2009
  Q: why is the cathode ray tube airless, what would hapen if it was a conductive liquid inside would the ...
  A: They'd move at the drift velocity due to molecular collisions. Kinda like a skydiver falls at ...
nuclear physics12/2/2009
  Q: Please tell me what are some of the branches of physics related to nuclear physics?
  A: Well, mostly there are sub-branches of nuclear physics such as nuclear astrophysics and cold neutron ...
Question from the TV show CSI: Miami12/2/2009
  Q: Mr. Nelson. My name is Jon and I'm a researcher for the CBS television show CSI: Miami. It's my job ...
  A: I usually don't give out contact information at allexperts.com, but they can look me up very easily ...
Van de Graaff generator top and a magnet12/1/2009
  Q: simple eg: negatively charged Van de Graaff generator top and a magnet. Put magnet near top. Would ...
  A: Well, right now what you're trying to talk about is moving electrons into the conductor and that ...
Van de Graaff generator top and a magnet11/30/2009
  Q: simple eg: negatively charged Van de Graaff generator top and a magnet. Put magnet near top. Would ...
  A: No, even electrons flowing in a wire in bulk have a surprisingly low drift velocity. Electrons in a ...
freezing kool-aid11/28/2009
  Q: I need help with my science fair project is this a goo d topic,"Will the amount of sugar affect the ...
  A: Well, it's testable and it answers a question, it's just that we already know the answer. So at ...
Circular motion11/26/2009
  Q: If you are swinging a stopper in horizontal uniform circular motion and stop the driving force ...
  A: If you simply stop applying the force necessary for an object to go in a circle, it will stop going ...
How many times the power would a sprinter have to produce to run ten times as fast?11/24/2009
  Q: I've been wondering about the relation of power to speed, and I'd like it if you could clarify some ...
  A: Terminal velocity is a measure of drag, yes. The problem now is that the situation starts to become ...
quantum physics11/22/2009
  Q: Something about this theory bugs me. Essentially it is all too complex to be true. The various ...
  A: The photon is one of the most-understood and best-studied objects in the known universe on every ...
chaos theory11/22/2009
  Q: aloha steve! i'd like to know: who coined the phrase 'sensitive dependence on initial conditions'? ...
  A: Well, I'm not really sure, but I'd say that Lorenz initially discovered that weather depended in ...
quantum physics11/21/2009
  Q: Something about this theory bugs me. Essentially it is all too complex to be true. The various ...
  A: Quantum mechanics bugs a lot of people, but it works fantastically well and it's stood up to nearly ...
How many times the power would a sprinter have to produce to run ten times as fast?11/21/2009
  Q: I've been wondering about the relation of power to speed, and I'd like it if you could clarify some ...
  A: You are, of course, assuming that air resistance is the main resistance to a runner's motion. At ...
electrostatics11/19/2009
  Q: what is it said that a moving automobile becomes charged ? ANSWER: Do you mean "why is it said" ...
  A: Air won't charge up a vehicle much, though it is another charging (and discharging) mechanism. Air ...
Re:11/19/2009
  Q: First off, I am not in school, I am trying to build a machine utilizing hydraulics to push something ...
  A: The equations all work, actually, because the distance listed accounts for the radius of part B as ...
electrostatics11/18/2009
  Q: what is it said that a moving automobile becomes charged ?
  A: Do you mean "why is it said" rather than "what is it said?" If so, then it's because an object like ...
observations11/12/2009
  Q: I know under the rules of the quantum, that when we observe a particle, we change it, but how do we ...
  A: I'll point you to this: http://www.aip.org/history/heisenberg/p08a.htm Based on some pretty ...
building catapults11/11/2009
  Q: I am not sure if you will be able to help me with my problem, if you cant it would be appreciated if ...
  A: I would suggest a combined approach. Use both the lead weight and the rubber band for energy, so ...
water bottle physics11/10/2009
  Q: Is there any physics laws that can be applied to water bottle covers cracking with normal usage? We ...
  A: This really seems more like a manufacturing problem, like you got a bad batch of plastic in those ...
Energy transformation11/10/2009
  Q: I have been teaching about energy transformation and transfer to a primary level class (7-8 year ...
  A: For your first one I'd need a picture, I think. I'm not sure what your toy looks like. For the ...
Water Suction11/8/2009
  Q: I hope I went to the right person for this question.. I have made a gold dredge and I am trying to ...
  A: Is the gravel under water or dry? This is kind of the opposite of an air lift used for salvage ...
Electron's location in any atom11/8/2009
  Q: My question is further to your reply on electron location. The below is your reply to somebody on ...
  A: You cannot simultaneously measure the position and momentum of an electron beyond a certain accuracy ...
magnetism - increasing magnetic flux11/7/2009
  Q: I'm curious as to how and why the magnetic flux increases for a magnet when you place stainless ...
  A: First, stainless steel is generally non-magnetic. Raw iron and ordinary steel are magnetic, but ...
Water Suction11/6/2009
  Q: I hope I went to the right person for this question.. I have made a gold dredge and I am trying to ...
  A: How do you get the air bubbles out? I mean, when you're under water the air has time to escape, but ...
Speed11/5/2009
  Q: How would I calculate the speed if given the % heavier than the true weight as a car goes through a ...
  A: The extra "apparent weight" of the car is due to centripetal acceleration of the car in the bottom ...
Acceleration due to gravity11/5/2009
  Q: How do I find the height above earth where the acceleration due to gravity at a percentage of its ...
  A: You use the basic formula for gravitational acceleration, GM/r^2 where G is the gravitational ...
Electron's location in any atom11/5/2009
  Q: My question is further to your reply on electron location. The below is your reply to somebody on ...
  A: No, these theorems are based on physical experiments with particles. An electron exists in an ...
The Classic Egg Drop11/4/2009
  Q: This year, my Junior Physics teacher wants our class to compete at the Physics Fair in the Egg ...
  A: Well, you could use rubber. It's biodegradeable. You could make a sling of rubber bands and put ...
Question11/3/2009
  Q: Sir, I've read that to locate an electron in a shell or in an atom, we have to pass a light of ...
  A: OK, there's a lot of things wrong here. Some gamma rays can have extremely small wavelengths (far ...
science fair expert talk11/3/2009
  Q: 1.Do you know much about bridge physics. 2.What would you say is the strongest bridge type: ...
  A: Bridges are just statics and strength of materials, but on a very large scale. Strength is as much ...
physics book for highschool student11/2/2009
  Q: I am looking for a book which is suitable for high school student that cover most of high school ...
  A: You might try Walker's book. Any book labeled Physics for Scientists and Engineers will be meant ...
Rate of ascent of weather balloons11/2/2009
  Q: The rate of ascent of a weather balloon is considered to be approximately constant, (although I've ...
  A: The rate of ascent is "approximately" constant. It does eventually slow down and stop. The ...
Calculations and Theory involved for Car Collisions11/2/2009
  Q: I'm not too sure if you may be able to help me, but any input ins very much appreciated. I had just ...
  A: I've gotten these questions before, they rarely turn out with definitive answers. That said, ...
Hello!!10/29/2009
  Q: my name is Jose and i go to a magnet school in the 6th grade. I am currently working on a project ...
  A: Now that we have a question and a test to work with, I can help. The density will be the first ...
nuclear physics10/28/2009
  Q: sir i want to know that when a beta particle is emiited from a nucleus ,an antinutrino is also ...
  A: Actually, we accept as tenets of physics that energy and momentum are conserved. We observe these ...
Hello!!10/27/2009
  Q: my name is Jose and i go to a magnet school in the 6th grade. I am currently working on a project ...
  A: A science fair project is a science project that answers a question. First, to be able to answer ...
hello10/24/2009
  Q: 1-why most people build their summer house near the sea? 2-why Lv "latent heat vaporization" it's ...
  A: Frist one, the evaporating water robs the air of heat. The ocean moderates the heat. The heats are ...
Inverted Pendulum on a moving platform10/23/2009
  Q: I am currently working on the effect of vehicle acceleration on standing passengers. For simplicity, ...
  A: Well, you seem to have all the mass at the end and a pendulum of length L standing nearly vertical ...
electromagnetic induction10/19/2009
  Q: A varying magnetic field is confined to an area smaller than that of a conducting loop surrounding ...
  A: Well, since flux is what matters and flux is field*area you would obviously use the *flux* over the ...
interview questions for science project10/18/2009
  Q: I'm doing a project on how far a Wooden Glider Flies if you change characteristics of the wings.This ...
  A: Some of your questions have answers, some don't. 1) A wooden glider has no thrust. Hence glider. ...
project10/18/2009
  Q: during our last conversation as i told u that i ve been doing a project so i need ed to ask u that ...
  A: Uranium-pigmented glass is already used in many things, however its from naturally occurring (i.e. ...
Spinning concentric spheres10/17/2009
  Q: Imagine a machine that consists of three perfectly balanced concentric spheres. (ie one iside the ...
  A: Sure, there might be some tiny precession of the individual spheres during acceleration, but the ...
Forces10/14/2009
  Q: This isn't a homework question, it is more of a question to generally understand physics and force ...
  A: Forces in general can be thought of as the exchange between two objects of a flux. Flux is kinda ...
physics10/13/2009
  Q: explain when a cup fall from a certain height 'h' then it broke into pieces why?and which type of ...
  A: The forces on the cup exceeded the shattering strength of the material it was made of during impact. ...
Particle physics10/6/2009
  Q: My Question is this:- Is it possible that the Higgs particle and the Graviton are one and the same ...
  A: No, by "particle" they still don't mean something like you envision (a grain of sand or a proton or ...
Unitary Operator10/5/2009
  Q: I have a question. Is it possible to apply a different unitary operator on the each component of a ...
  A: This sounds like a quantum mechanics question, but the way it's phrased I can't tell exactly what ...
energy conservation10/5/2009
  Q: This may or may not be your type of question, but I don't know any other field to submit it to. ...
  A: This depends on a couple factors of the dryer's design, but the basic thermal physics of evaporation ...
Ice10/2/2009
  Q: if i were to put a ice into a bowl of liquid than is constanly below 0 degree celcius and the ice is ...
  A: Technically there's a thermal probability even below freezing that the water molecules will diffuse ...
please help9/30/2009
  Q: ,i was wondering if u could help me with this, i need the general equation of motion. a robot is ...
  A: Well, since I know nothing about its walking motion then no I can't. Or about the magnitude of this ...
Depth and distance perception9/29/2009
  Q: I have read quite a bit about these and am trying to determine what factors would affect these and ...
  A: Motion of a viewer doesn't really affect depth perception of an object which is stationary relative ...
kinetic sculpture9/29/2009
  Q: I am trying to make a wind driven sculpture. This sculpture will have several points of rotation. ...
  A: The principle difference between his design and yours appears to be one of symmetry. His has more ...
Prism9/29/2009
  Q: i know that when white light passes through a prism, it would diffuse into 7 colours, but when it ...
  A: It'll separate, just like light passing through a prism, the bend angle will just be the opposite ...
magnetic strip9/29/2009
  Q: I have a card at school-much like a credit card. i can use it at the school store. The magnetic ...
  A: Heat can de-magnetize materials. Unfortunately, what you have on your card isn't just ...
light9/27/2009
  Q: Is the space really empty(no medium)? Then how a wave(light wave) can travel in that empty space?
  A: Empty space isn't really empty. There are quantum particle/antiparticle pairs popping in and out of ...
Particle Accelerator9/27/2009
  Q: I am attempting to build a traditional particle accelerator using a van de Graff and a Vacuum tube. ...
  A: OK, let's start with some basics. First, particle accelerators require licenses. They're not hard ...
Self Quenching In Geiger-Muller Counter9/26/2009
  Q: Can you please explain the following (the capitalized text)? "The ions of the quenching gas reach ...
  A: A Geiger counter is an avalanche detector, relying on runaway multiplication of electrons. A ...
The Earth9/25/2009
  Q: when we are at the bottom of the earth(South Pole), we are able to stand and not fall off the earth ...
  A: You're assuming that the person in the spaceship has a spaceship whose roof always points North. If ...
Science9/25/2009
  Q: when we take a lift from a higher level to a lower level, am i right to say take when the lift is ...
  A: It would reduce their impact speed, but you can only jump up a couple of feet in the air. This was ...
physics9/23/2009
  Q: why a swimmer diving into a pool of water doesn't get hurt?
  A: The forces on a swimmer diving into a pool of water, because the water moves out of the way, are not ...
Measurement Questions9/23/2009
  Q: Im a 8th grade student and part of our homework is to ask a scientist questions. These are our 5 ...
  A: Well, I don't usually answer homework questions but I'll point you to resources where you can do ...
Pumping with Compressed Air9/23/2009
  Q: I recently asked this question of James Kovalcin. I have a follow up but apparently he is ...
  A: It should work. The only way it wouldn't work at all is if the air on the supply to the controller ...
Physics inside a galvanic cell9/22/2009
  Q: I am puzzled about the physical forces acting on charge carriers inside a simple cell. My ...
  A: In a battery like the Daniel cell or the Gravity Cell (a variant): ...
Pumping with Compressed Air9/22/2009
  Q: I recently asked this question of James Kovalcin. I have a follow up but apparently he is ...
  A: 200 meters of supply line? That will reduce pressure dramatically, depending on flow rate and ...
Pumping with Compressed Air9/21/2009
  Q: I recently asked this question of James Kovalcin. I have a follow up but apparently he is ...
  A: I can't fault his math or his physics, it really should pump that high and only the vertical rate of ...
Quantum theory9/20/2009
  Q: Do you know any websites where I can computer simulations that presented important concepts of the ...
  A: This guy has a whole mess of neat ones: http://www.falstad.com/mathphysics.html This one's for the ...
Physics inside a galvanic cell9/19/2009
  Q: I am puzzled about the physical forces acting on charge carriers inside a simple cell. My ...
  A: Focus on the piece about the salt bridge. A battery needs something to neutralize the ion buildup ...
Irrational values in a real universe.9/18/2009
  Q: Can the physical characteristics (velocity, temperature, mass, etc.) of tangible objects have an ...
  A: Pi isn't irrational, it's transcendental. Meaning it goes on forever without ever repeating its ...
Science fair help9/15/2009
  Q: Hey there! My name is Jenny, and I was wondering if you had any science fair project ideas on ...
  A: OK, for astronomy projects there are a few out there like this: ...
clinker9/15/2009
  Q: I am studying the frequency distribution of size of crystals in a cement clinker. As a clinker is ...
  A: This is definitely outside my regular field of expertise, but I did a quick search anyhow and found ...
Science fair help9/14/2009
  Q: Hey there! My name is Jenny, and I was wondering if you had any science fair project ideas on ...
  A: The problem is that you've picked a very specific area of physics. General relativity is extremely ...
Beer eruption9/14/2009
  Q: Question is related to a screenplay I'm writing. I couldn't find a good explanation on the ...
  A: This is actually a really good question, because I've seen this (my friends used to do this in ...
Science fair help9/13/2009
  Q: Hey there! My name is Jenny, and I was wondering if you had any science fair project ideas on ...
  A: Technically you're stuck, since relativity projects don't currently have practical applications and ...
Magnetism9/10/2009
  Q: Respected sir I am a student of class 12 How do birds navigate using the earths magnetic field ?
  A: This is a little outside my area. It's believed that magnetite deposits in their beaks allow them ...
nuclear physics9/10/2009
  Q: what if depleted uranium is used in braces or any other isotope from nuclear waste could be used in ...
  A: Basic experiment involving nuclear waste? No. It takes special equipment and training to handle ...
quantum9/10/2009
  Q: I previously asked a question relating to a electron or any wave function, inside a box, covering ...
  A: The wavefunction does collapse upon interaction, it's actually still a distributed thing until then. ...
Color effect in B & W program9/9/2009
  Q: I've been wondering about this for the longest time, and was hoping that you'd be able to explain ...
  A: Only when you have grids? And is it particular to your TV? If so then I'd say you're getting a ...
quantum9/9/2009
  Q: I'm reading a book by Paul Davies and need to clear something. I understand teh quantum has its own ...
  A: If I have a Geiger counter, it's fully capable of resolving the decay of a radioactive nucleus like ...
nuclear physics9/8/2009
  Q: what if depleted uranium is used in braces or any other isotope from nuclear waste could be used in ...
  A: First, think of fuel recycling: http://www.nationalcenter.org/NuclearFastReactorsSA1205.pdf The ...
Weird Atom based Sci-fi Query :)9/7/2009
  Q: I’m betting this may be one of the weirder questions you’ll get today. There is, however, method to ...
  A: OK, so your guy wants to commit suicide and dissociate into individual atoms. Relatively easy, ...
quantum9/7/2009
  Q: I'm reading a book by Paul Davies and need to clear something. I understand teh quantum has its own ...
  A: It's not magic. Upon interaction, the wavefunction of a particle collapses to a definite state. It ...
distance9/7/2009
  Q: I want to increase the distance in my spring loaded gun. How do I do that I want a 2 or 3 ounce ...
  A: You'll need to be more specific, I have no idea what your design looks like or what the spring ...
wind-up hybrid vehicle9/6/2009
  Q: How is it impossible to power a vehicle using the idea of torsional springs as in wind-up toys,if ...
  A: Weight and durability. Springs have very low energy densities compared to their sizes. If you make ...
nuclear physics9/5/2009
  Q: what if depleted uranium is used in braces or any other isotope from nuclear waste could be used in ...
  A: Braces? Well, it is incredibly dense material, and I've heard of it used in bullets, aircraft ...
energy in humans9/4/2009
  Q: I attended a recent lecture on the mind. One of the main things that was said is that they can ...
  A: I believe you mean "sort of" and not "sought of," as well as "exists" and not "exits." That said, ...
nuclear physics9/4/2009
  Q: im doing a science project and its research based project and im working on recycling of nuclear ...
  A: Uranium is a heavy metal and therefore not good for you chemically. Depleted uranium is really not ...
physics9/4/2009
  Q: Cats have nine lives Folks claim that “cats have nine lives” because when they are thrown at a ...
  A: Cats generally land on their feet because while angular momentum is conserved they can alter their ...
Time and Energy9/2/2009
  Q: I was thinking about time travel and one thing still puzzles me. Energy can't be created or ...
  A: You'd be relocating it in spacetime, until the point where you sent its original copy back in time. ...
Car crash9/2/2009
  Q: I was driving across a roundabout, a girl in a car was not looking and drove into me. Her offside ...
  A: On the face of it, you'd appear to be right about the sternum and the direction, but I'd need photos ...
few questions9/2/2009
  Q: 1)which of the follwing travels faster in optical fiber, uv lighy, invisible IR ,visible light, or ...
  A: 1) That depends on the dispersion relation in the particular optical fiber, and there are two kinds. ...
astrophysics science fair project idea9/2/2009
  Q: I am in the 8th grade, but I am highly capable of a 12th grade project. I was wondering if you could ...
  A: The vacuum that we can create on Earth is nowhere near as good as the vacuum that gravitation ...
Evanescent Wave Project8/31/2009
  Q: I am a college freshman and am involved with a junior physics program in which we help middle ...
  A: This is pretty specific and a little outside my subfield, but I'll try to help you out. First, a ...
windmills8/31/2009
  Q: I am trying to make a windmill. Please look at my sketch. Can you think of an answer to my two ...
  A: Well there's no material I know of that acts as a one-way valve for air, and no static structure. ...
color8/31/2009
  Q: why dont red, sunburned feet look as red above water than they do underwater?
  A: Well that depends on the water and the background. I always thought sunburned feet looked more red ...
massless particles8/27/2009
  Q: its been brought to my attention that there may exist particles that contain no mass. If so, I have ...
  A: Photons are massless particles. In physics, the word "particle" is used to mean that it is absorbed ...
Classical Physics8/26/2009
  Q: Sir, I have few doubts in using Newton's second law F = ma. Consider the following situation. ...
  A: You won't observe a force that has a proportionality constant equal to the mass, that's what's ...
physics8/26/2009
  Q: How can I design an experiment to measure the center of gravity of doughnut, if I know its center is ...
  A: An actual doughnut or a torus of general material? I guess that doesn't matter, just use the ...
microwave damage to water8/25/2009
  Q: <my health food friends tell me that you should not eat food from the microwave because it destroys ...
  A: No, that's crazy-talk. The microwave doesn't destroy all nutrients and it absolutely will not alter ...
problem in physics8/25/2009
  Q: SIR,THANKS FOR ANSWER THAT THE ROPE'S VELOCITY IS THE COMPONENT OF BLOCK'S VELOCITY.BUT I HAVE ONE ...
  A: No, even if the angle theta that you draw is not 45 degrees you can draw a right triangle. It ...
Classical Physics8/24/2009
  Q: Sir, I have few doubts in using Newton's second law F = ma. Consider the following situation. ...
  A: If there was a force proportional to the acceleration of the charge, then it could not have this ...
theory8/21/2009
  Q: Now you know how gravity and mass effect each other. How they both manipulate the other. And how ...
  A: Only huge densities of light energy could do that, but yes. Here's a related paper. Einstein's ...
electrostatics8/21/2009
  Q: a very long straight uniformly charged thread carries a charge lambda (k) per unit length. find the ...
  A: Something's missing from the answer, because the way you stated the question the answer is off by a ...
gravity and friction8/21/2009
  Q: what are some of the effects of gravity and friction on speed?
  A: The answer is entirely situation dependent. Are you talking about kinetic (sliding) or static ...
Physics8/17/2009
  Q: Consider a body (For example a metal Sphere). What will be the forces acting on the body if it is ...
  A: Sure, if it's designed right. The system will settle to a stable state after a while (you're ...
Secondary wavelets8/14/2009
  Q: I read about the Huygens priciple of secondary wavelets and how they act as sources of disturbance ...
  A: Light is an electromagnetic wave, which does not travel through a medium like water waves. Its ...
Secondary wavelets8/14/2009
  Q: I read about the Huygens priciple of secondary wavelets and how they act as sources of disturbance ...
  A: Why would they suddenly stop and go backwards? That would violate conservation of momentum. The ...
gravitation8/12/2009
  Q: what is the main difference in the newtons gravitatinal view and that of eistein in which einstein ...
  A: Newtonian physics assumes that light travels at infinite speed, and that the force of gravity simply ...
capacitor8/12/2009
  Q: i wanted to ask that why in a capacitor the charges are not neutralised when there is no dielectric ...
  A: You'll notice lightning discharges after building up. You need to reach a voltage of roughly (rule ...
physics8/11/2009
  Q: Mr. Steve :-) If a curve with a radius of 88 m is banked for a car travelling 75 km/h, What should ...
  A: Well, you asked me what it should be but you already know the answer. You're going to have to ...
gravity8/11/2009
  Q: How the gravitational energy get conserved in earth(for example)? It is attracting each and ...
  A: You seem more to need the law of conservation of energy explained. The rest of this sounds like ...
light8/11/2009
  Q: What is real and virtual image? And tell me about diffraction, interference and polarisation please.
  A: I'll explain part of this and then refer you to hyperphysics because you don't have a specific ...
atom question8/6/2009
  Q: what happens inside an atom when it is excited by a collision
  A: The wavefunction (basically, the spatial distribution) of an electron in an excited atom spreads out ...
electricity8/6/2009
  Q: I was surprised to read in a textbook that although we understand electricity enough to describe its ...
  A: Electricity is the flow of charges. We play with charges all the time and know quite well what they ...
current as a vector8/5/2009
  Q: Sir, Why can't current be treated as a vector? It has both magnitude and direction. ANSWER: ...
  A: Anyone who's really concerned with the answer to this is definitely overly concerned with semantics. ...
uncertainty and light8/4/2009
  Q: We know that by the De broglie's theorem, the momentum of a light photon traveling at the speed of ...
  A: No, not without experimentation. You're assuming its direction and such, momentum is a vector. And ...
General science vocabulary8/4/2009
  Q: A scientific statement (often mathematical in form) that summarizes experimental data is called a ...
  A: One of the great conundrums in physics, why is it that we call a law a law and a theory a theory? ...
Force an a charge8/3/2009
  Q: Sir, I have got into another confusion regarding Lorentz forces. Let's consider the following. ...
  A: Wow, I had a whole long answer to this typed up yesterday and didn't hit the second send button... ...
shapes of galaxies8/3/2009
  Q: Sir, I have got into confusion after thinking of the following effects. I think the forces which ...
  A: I'll get to your more complex question tomorrow when I have some more time. But this one is easy. ...
Science experiment help?8/3/2009
  Q: i was wondering if you could help me with my science experiment. I need to provide research for my ...
  A: That would probably depend on which surface absorbed the least energy. So you're looking for ...
photoelectric effect7/31/2009
  Q: how is the stopping potential a measure of max kinetic energy of electrons and how come the ...
  A: Well, this is somewhat situation dependent, you have to know both the photon energy and the work ...
shapes of galaxies7/31/2009
  Q: Sir, I have got into confusion after thinking of the following effects. I think the forces which ...
  A: Your first situation, observer A would also see time moving slower for those particles, ...
shapes of galaxies7/31/2009
  Q: Sir, Are there proven theories which explain the various shapes of galaxies? To my knowledge I ...
  A: Astrophysicists may tell you they have a theory that does it, but galaxy formation is still a ...
ENERGIES7/30/2009
  Q: when an electron add in an atom , energy is released......this energy is released because when the ...
  A: First, the sign of the electron charge (q2) is negative. So when it's attracted to a positive ...
Mirage7/30/2009
  Q: Hey all! I'm kind of worried. Today I went to the univ. and it was a hot summer day. As I was ...
  A: I don't have a photograph to work with or anything, but I would say it was still an effect of ...
Gravity7/28/2009
  Q: Is there gravity at the exact center of the earth? In other words, would equal mass in all ...
  A: Yes and no. The forces will all cancel out, so there will be no gravitational forces. Time will ...
Complicated Mu Issues7/22/2009
  Q: I've been working on a detailed project that's about the 'Physics of a Merry-Go-Round,' and I'm ...
  A: Your question doesn't make it clear what the goal of your calculation is. Are you trying to figure ...
wind energy7/21/2009
  Q: What is the difference between a Baker Wind Turbine and a propeller driven windmill?
  A: Well, since the name of the questioner appearing on this question and the invention are the same and ...
eclipse7/21/2009
  Q: There will be an eclipse on the 22nd and one of the concerns is with the disruption to communication ...
  A: Nothing at all. However, people gather in open spaces away from cell phone towers to watch ...
physics7/21/2009
  Q: Steve If a person is standing above a car, and this car starts to move, after that he jumps, what ...
  A: OK, I'm wondering if you asked this question quite the way you meant it. Is he standing on the car ...
Quatum theory7/20/2009
  Q: Calculate the energy range, in eV,of photons in the visible region of the electromagnetic ...
  A: Each of those wavelengths corresponds to an energy, since you have a range of wavelengths you have a ...
lasers7/20/2009
  Q: we are supposed to do an experimental project on laser and total internal reflection of lasers can ...
  A: I think they intended for you to come up with something like "how fiber-optic communications works." ...
How to prevent the Ringing effect and the decision of the secondary coil parameters ?7/19/2009
  Q: In this new treatise we will discuss some important questions about RLC circuits and resonance ...
  A: Birol, I still don't understand the overall goal of these coils. What exactly are you trying to ...
inclined plane friction help7/19/2009
  Q: I am doing an EEI. My experiment was to roll golf balls down an inclined plane in order to test ...
  A: "f" is the force of static friction. Multiplied by its radius, that gives you the torque, which ...
Physics - Kinetic Energy conversion7/19/2009
  Q: I don't often wonder about such things but a couple of weeks ago I did and this popped out.... ...
  A: Obviously it's a continuous process and not instantateous. You just have to look on a small enough ...
problem in physics7/18/2009
  Q: SIR,THANKS FOR ANSWER THAT THE ROPE'S VELOCITY IS THE COMPONENT OF BLOCK'S VELOCITY.BUT I HAVE ONE ...
  A: No, it's not a parallelogram (look at the drawing, the sides are in no way parallel). It's two ...
physics7/18/2009
  Q: we are agroup of teachers in training course and we would like your help to answer some questions ...
  A: 1) Impossible to answer, who is to say what is the most important research? It could be anything ...
Gasoline7/17/2009
  Q: Will you please help me with some suggestions on how to build my invention, the NoGas Engine? I ...
  A: The coefficient of expansion of gasoline is approximately 0.0006/degree F. You can multiply be 9/5 ...
2 masses!7/17/2009
  Q: I'm a guy from India currently preparing for the entrance exam of the IIT(Indian Institute of ...
  A: OK, the problem is slightly weird. Your solution is great for a steady state, but if they start ...
problem in physics7/17/2009
  Q: SIR,THANKS FOR ANSWER THAT THE ROPE'S VELOCITY IS THE COMPONENT OF BLOCK'S VELOCITY.BUT I HAVE ONE ...
  A: No, it's just like the previous problem. Rotate it 90 degrees clockwise, block out the lower ...
Cern7/16/2009
  Q: We all know Cern can change way of the physic.Altough it is very very important experiment we can ...
  A: CERN is currently repairing the Large Hadron Collider, but has another large collider still in ...
physics7/16/2009
  Q: REVEREND SIR, I HAVE A QUESTION.WHEN A BLOCK IS CONNECTED TO A ROPE AND THE ROPE IS ...
  A: I'll go back and modify my answer (so no one else gets confused), upon looking at it I was thinking ...
see by all electromagnetic waves7/15/2009
  Q: if we could see by all range of electromagnetic waves,what we see,and how we see the world and all ...
  A: Well, that's physically impossible...nothing is sensitive to the infinite range of electromagnetic ...
optics.7/15/2009
  Q: how a trick mirror is made? why are shaving mirrors concave while rear view mirrors convex?
  A: A trick mirror is made the same way any other mirror is made. Glass is cast in a shape, polished, ...
Heat from electromagnetic waves 27/14/2009
  Q: Days ago, I asked you about the heat produced by electromagnetic waves. I was thinking that some ...
  A: The thermometer either absorbs infrared better than visible light (meaning that visible light is ...
length of a curb lever7/14/2009
  Q: would you pls explain me ; if i use a curb shape lever rather than a hard straight one .considering ...
  A: For this situation it will increase slightly, as the distance between the fulcrum and the end of the ...
Fusel Oils7/14/2009
  Q: What is the boiling point of fusels oils at atmospheric Pressure?
  A: You don't need me, wikipedia has a well-researched section on this: ...
hollow sphere7/14/2009
  Q: can an object float inside a hollow sphere,which is placed in a gravitational field?
  A: Do you mean, will the hollow sphere shield the object inside it from gravitation if the sphere is ...
length of a curb lever7/14/2009
  Q: would you pls explain me ; if i use a curb shape lever rather than a hard straight one .considering ...
  A: Point of grammar: it's spelled "curved" and not "curbed." 1) I'll assume you have the fulcrum in ...
Ray Optics- Caustic curve7/13/2009
  Q: i beg that you kindly explain to me this phenomenon, i have failed to understand it. Our teacher is ...
  A: This term isn't commonly used in physics classes anymore, I believe it's a bit archaic. I'd heard ...
Frictionless surface7/13/2009
  Q: Is it just a mathematical approximation that on a frictionless surface since no obstruction ...
  A: It's not zero, it just tends towards zero. That's not the same. You need nearly zero force on a ...
velocity vector entering a magnetic field7/13/2009
  Q: I'm trying to understand a question. An electron with velocity vector v e- enters a magnetic ...
  A: Easy, use the right hand rule and remember that the sign of the charge is negative. You take your ...
velocity vector entering a magnetic field7/12/2009
  Q: I'm trying to understand a question. An electron with velocity vector v e- enters a magnetic ...
  A: Your rough sketch in text did not make it through. Since you know the answer, I won't consider this ...
Tesla7/12/2009
  Q: Iread somewhere that Tesla was able to transmit electrical power without wires.He was able to light ...
  A: Basically, induction is a very general term. Also he could pass it through his own body at very ...
Optical Illusion7/11/2009
  Q: I'm a cyclist, and have noticed that from a distance all hills look like they're going to eat you ...
  A: I can think of two explanations, which are both human. Kinda like how the sky isn't actually blue. ...
Ice engine7/11/2009
  Q: Will you please help me with some suggestions on how to build my invention, the ICE ENGINE? Here is ...
  A: This is a fascinating concept, aside from two tiny but enormous flaws. The first is obvious, speed. ...
The Honey Dilema???7/10/2009
  Q: I was taking some honey from a jar of set Honey and the strangest question entered my mind! If you ...
  A: Then honey must be a non-Newtonian fluid like Oobleck. Try mixing a 50/50 mixture of corn starch ...
Capacitance quandry7/10/2009
  Q: I am experimenting with high voltage capacitors and was wondering if you could explain what I am ...
  A: The small spark is from the difference in voltage, but there's no conundrum here. The charges on ...
Force7/8/2009
  Q: I recently read in a DMV book that the force is 4 times greater (not 2 times) for a vehicle ...
  A: They mean the force needed to stop you in the same distance. Force*distance = energy. Kinetic ...
Quantum Physics7/8/2009
  Q: I'm 13 years old, and i was wondering if you could explain quantum physics to me in the most ...
  A: Attempting to find a simple explanation for quantum physics is relatively futile. The simple and ...
Electric current7/7/2009
  Q: When you touch an electric wire while standing on the ground, you get shocked! How an electric ...
  A: Yes, due to its large area the ground is an excellent conductor. The fatter the wire, the better ...
Battery and Leyden jar7/7/2009
  Q: What's the difference between battery and Leyden jar?
  A: A battery stores energy in chemical form and does not contain excess buildup of charges. It creates ...
Synthetic Telepathy7/3/2009
  Q: My family and I have been under electronic attack since at least 2007. I know the individual who is ...
  A: I do know a good bit about this. I've worked on some of the most sensitive types electronic devices ...
color and wavelength7/3/2009
  Q: on your webpage i have found an answer of Curtis to one question on physics, it is says, the energy ...
  A: This could mean two things, so I'm going to address it first as if you're talking about light. ...
physics7/3/2009
  Q: I have to make a working model or perform an experiment related to "Physics in kitchen" .Could you ...
  A: Fortunately, you don't need me. My kitchen physics experiments are usually unnecessarily complex. ...
fatal car accident7/3/2009
  Q: my husband was in a fatal car accident. Law enforcement explained the accident as follows: the car ...
  A: I'm sorry for your loss. Based on the few details presented here and the complexity of a car crash, ...
Heat from electromagnetic waves7/2/2009
  Q: I would like to know the next: Does every wavelength of radiation increase temperature of materials ...
  A: The answers to these question are by no means simple and you haven't provided enough information for ...
Synthetic Telepathy7/2/2009
  Q: My family and I have been under electronic attack since at least 2007. I know the individual who is ...
  A: OK, your question is somewhat incomplete and will require a follow-up before I can answer it. The ...
nucleus7/1/2009
  Q: In beta decay, does the atom get oppositely charged when an electron or positron is emitted? And do ...
  A: They do, conservation of charge demands it. The jury is still out on your second question, I have a ...
Eddy Currents6/27/2009
  Q: I know that for a corrent to flow you need a driving source like an emf.In the case of eddy currents ...
  A: EMF stands for electro-motive force. That's induced by changing magnetic fields. So when you have ...
reflection6/25/2009
  Q: I read somewhere that light is an EM wave and in relation to this wave theory can you help me ...
  A: Let me approximate this... Waves reflect from surfaces. Electric fields in an EM wave hitting a ...
NUCLEAR PHYSICS6/25/2009
  Q: Am a 200 level physics student of Ahmadu Bello University Zaria, Nigeria. I want to know the ...
  A: I'm not sure what a 200 level student is, your system is different. Nuclear physics studies the ...
Electricity6/24/2009
  Q: Can you explain how this works or is it some kind of hoax? candles.wmv ANSWER: You'll have to ...
  A: OK, I got it. I've seen plenty of videos on youtube, and this one has a few tells: 1) Timing. ...
Electricity6/24/2009
  Q: Can you explain how this works or is it some kind of hoax? candles.wmv ANSWER: You'll have to ...
  A: There's only a link for attaching pictures on the question form. Therefore, you're either stuck ...
physics of light reception6/24/2009
  Q: assume a light is glowing at a long distance.that source wont give light to our vicinity because of ...
  A: Well, if a light is shining from far enough away we won't see it. There are stars which are too ...
physics6/23/2009
  Q: what will happen if earth stops to revolve around sun? what will happen if earth stops spinning?
  A: So, you're assuming two things which are physically impossible, but that the rest of physics works? ...
Fields6/22/2009
  Q: As usual..yr answers are excellent!! Thank You. In an Electric Field,,what is is when we say a Field ...
  A: It means that the change in energy due to the field (in the case of an electric field, due to the ...
investigatory project6/21/2009
  Q: can you please give me some easy investigatory projects related to physics?
  A: Yes, but I need to know a few things if you would follow this up. Your age and knowledge of ...
fire6/21/2009
  Q: When you light up a candle, the flame will glow in a triangle like shape. Why can't it take any ...
  A: That's relatively complex fluid dynamics, if I were to calculate the shape, but for an intuitive ...
Physics Application6/20/2009
  Q: I will be taking part in a Science Challenge in July.Earlier,the challenge were conducted in several ...
  A: Well, you pretty much listed some already, and I'm not psychic. Perhaps it would help to look at ...
heat energy6/18/2009
  Q: Nelson, I am wondering if there is any equation to calculate how much energy (heat?) an object is ...
  A: This is actually quite complex. It depends on the temperature of the flame, the thermal ...
Rocket6/17/2009
  Q: I am looking to design a own model rocket, i should know some information please help mme How ...
  A: Calculation of the height is pretty simple if you know your engine type, there are calculators out ...
Quantam Physics6/10/2009
  Q: What is quantam physics...how can we make a lay man understand the concept in a simple manner.
  A: Haaa ha ha ha! If I knew how to make a lay person understand quantum mechanics I'd have published a ...
The Stand6/8/2009
  Q: I'm re-reading Stephen King's "The Stand". Early in the novel several major cities lose power, ...
  A: No, the reactors would be shut down and there would be NO power coming from them, starting as soon ...
The Stand6/8/2009
  Q: I'm re-reading Stephen King's "The Stand". Early in the novel several major cities lose power, ...
  A: Unmanned? That's now how they run. If careful operators were unavailable even for a minute the ...
Atomic Behaviour6/7/2009
  Q: Does one atom of isolated hydrogen have a temperature? If one atom was n space with no gravity ...
  A: Sure it does, relative to whatever is measuring its temperature. It will have a velocity relative ...
A/D converter/ion6/6/2009
  Q: I built a data logger and an 8 bit digitizer then realized that some were using 12 - 24 bit ...
  A: Yes, Ron, the ADC would be uselessly overcomplicated if one were limited to that screen and plotting ...
electric power requirement for generation of sparks6/6/2009
  Q: could you please tell me how much (minimum electric)power would be required to produce electric ...
  A: A whole mole? That's 22.4 liters of an ideal gas at STP (with only small deviations for other gas ...
working model on physics6/5/2009
  Q: please give me ideas for making working model on any topic of physics like light, electricity, ...
  A: No need to reinvent the wheel, just check out demonstrations (in effect, working models) at places ...
Power line vibration6/5/2009
  Q: I often walk under a point where two power lines cross. The local line along our street crosses ...
  A: There's gotta be some coupling between them at 120 Hz. If you drive a mechanical system at its ...
Question concering falling down and odds to survive.6/4/2009
  Q: Can a person survive entering water at 300KM/h in vertical position with toes pointing down? How ...
  A: 300 km/h? No, at that speed there's no diving position that would allow one to survive. So ...
Mass6/4/2009
  Q: Does surface area have an affect on mass? Does changing the surface area of something change it's ...
  A: No, mass is the quantity of matter in an object. If I squish a sphere of clay flat I change its ...
draining water6/3/2009
  Q: If you have 2 containers half full with water and a tube to the ground. The first is 1 foot off the ...
  A: Are you talking about siphoning the water or just draining it out the bottom? Does the tube go the ...
electromagnetic shielding5/26/2009
  Q: actually i was wondering if there were other ways to stop electromagnetic waves beside using ...
  A: Large amounts of less-conductive material? That's still a Faraday cage, I guess. I guess you could ...
curriculum questiom5/26/2009
  Q: I am from Kuwait and I want to know about the curriculum of physics in other countries because I ...
  A: Well, the only obvious thing you're missing is fluid mechanics (buoyancy, Bernoulli's equation). ...
throw5/26/2009
  Q: When rain (with constant velocity), if you want walk from one place to another place how can you go ...
  A: Well, I'm not going to prove it mathematically because that might constitute the solution to a ...
Escape velocity5/25/2009
  Q: Dr. Nelson, I just asked this question of another expert, but his reply was 2 screens of math ...
  A: Escape velocity depends on how far out you achieve that velocity. You have to set the kinetic ...
Practical limitations of submarine periscope-mounted surface search radar5/25/2009
  Q: Nelson, Thanks very much for your willingness to answer questions, and I apologize if this ...
  A: A Stirling engine is more efficient, but not air-independent. Anyhow, your question about the ...
curriculum questiom5/24/2009
  Q: I am from Kuwait and I want to know about the curriculum of physics in other countries because I ...
  A: That depends on the level of physics they study. Generally, they spend one semester on classical ...
Collisions, Momentum and Energy5/24/2009
  Q: I don't fully understand how momentum is always conserved in a collision, yet kinetic energy can be ...
  A: It's not "lost," it's just converted to another form of energy. Conservation of momentum is one of ...
rocket5/22/2009
  Q: I'm working on building a rocket with an A8-3 engine. Before liftoff i have to answer some ...
  A: The formula is correct, but assumes no friction. The real value will be considerably lower of both ...
Laser Defraction5/22/2009
  Q: I'd like to be able to defract laser light from my laser point in a number of ways. For example ...
  A: They contain spinning mirrors that will fan the beam. The the human eye it'll look like multiple ...
rope suspension bridge building5/21/2009
  Q: i have been wondering how rope suspension bridges were built in ancient times {Incan for ex:}. more ...
  A: Well, generally someone had to climb down and up the other side. Bridges weren't built to help the ...
SPEED & GRAVITY5/21/2009
  Q: mars has a gravity 38% that of earth...if earths gravity was the same how fast will a man be able to ...
  A: Depends on the person, the animal, the bullet, or the car of course. Friction isn't usually the ...
physics5/21/2009
  Q: From what i understand if you are travelling in a vehicle at 100 km an hour and dropped an object ...
  A: Nope, in fact she's exactly wrong. A dropped rock would have the same velocity at first, then it ...
PV hydrogen fuel5/20/2009
  Q: Hopefully this isn't too basic, but it seems so obvious to me. If you set up a Photo Voltaic cell, ...
  A: It's not a matter of simplicity, it's a matter of cost and wattage. Solar, to those who grew up ...
electromagnetic waves5/19/2009
  Q: Could you please explain the following sentence why it is correct? The field strengths are great in ...
  A: Without advanced math and in-depth physics this will be difficult, but picture light like a water ...
arc length5/18/2009
  Q: i am attempting to determine the arc length of a baseball without using calculus. i would be very ...
  A: Well, how did you figure out the x velocity? You really have to integrate the total velocity. So ...
Impact5/15/2009
  Q: I work in product development within the glass industry in the UK. We are developing products to ...
  A: I'm confused by your question, what exactly do you need an expert for, help calculating energy or ...
Rivers and ponds5/14/2009
  Q: How are the volume of water, total distance covered and depth of large rivers and deep ponds ...
  A: Volume is calculated. Area covered can be measured from satellite photographs, check google Earth ...
Electric question5/13/2009
  Q: I am researching a story that I am working on, and am having difficulty locating decent information. ...
  A: This is more of a biology question, but I know Glen Elert answers questions like this with his ...
motors5/11/2009
  Q: which is the most powerful pound for pound engine or motor can you get the same power or more from ...
  A: See here: http://www.uqm.com/pdfs/PowerPhase150%20(2.4.09).pdf This is an example of a 200 HP ...
heat5/10/2009
  Q: If there is water in glass of 20K temperature in room the room is also equal to the water ...
  A: Heat is transferred in and out of the water at the same rate. The room and the water are in thermal ...
How can I work at the saturation point B ?5/10/2009
  Q: I am sending you some informations about you answer. For the application of a toroid you are ...
  A: My mistake, in looking into mu-metal this appears to be why they're not used in power transformers ...
ROTATIONAL MOTION5/9/2009
  Q: Q: I find that whenever a body is executing some sort of rotational motion, the body is at its ...
  A: The simple answer, without dragging you through the mathematics and cross products, is that rotating ...
Pressure decreases when adding more weights?5/7/2009
  Q: Steve, (see attached picture) Q1. If you put a weight of 1 pound (and an area of 1 sq. inch) on a ...
  A: For question one, the answer is yes that the gauge will read 1 PSI. The reading will not decrease ...
MASS5/6/2009
  Q: Q: Right from the schooldays i have been taught the concept of mass as such without differentiating ...
  A: Inertial mass is an object's resistance to acceleration. Gravitational mass is an object's ...
EM SPECTRUM5/6/2009
  Q: Q3.I think nature has given an undue importance to a particular region in the EM spectrum.This is ...
  A: I thought I'd followed up on this. "Gamma rays" and "radio waves" are the same thing: photons. We ...
ELECTROMAGNETISM & GRAVITATION5/5/2009
  Q: Q1:We use electric or magnetic lines of force to deal with most of the problems in electricity and ...
  A: This is largely historical, and the use of "lines of force" is somewhat outdated. Also, magnetic ...
COMPLEX NUMBERS5/5/2009
  Q: Q:In maths we speak of imaginary nos.What is the real physical meaning of these nos.What is the ...
  A: They're a mathematical tool do describe things whose physical laws behave the same way ...
HEAT RADIATIONS5/2/2009
  Q: Q:Why the infrared rays alone should carry heat and why not other radiations(say light or X-rays) ...
  A: Visible light does heat us up, actually. IR doesn't necessarily irritate people, just heat their ...
DEBROGLIE WAVELENGTH5/2/2009
  Q: Q:The DeBroglie wavelength of a particle is given by lambda=h/mv. Two properties of a particle ...
  A: Well, the words "fuses up" is an incredible sweeping under the rug of a lot of mathematics and ...
Rotation of Rigid bodies5/2/2009
  Q: Greetings sir, I am a first year university student.I would like to grasp some basic concepts ...
  A: Presumably you *always* try to use the correct formula. Yes, 1/2MR^2 is the correct form for a ...
HEAT RADIATIONS4/30/2009
  Q: Q:Why the infrared rays alone should carry heat and why not other radiations(say light or X-rays) ...
  A: It doesn't, that's just the range of the peak frequencies emitted in the energy distribution by ...
Quantum entanglement4/30/2009
  Q: Q:What is quantum entanglement? How to make two particles quantum mechanically entangled? Is this ...
  A: Quantum entanglement deals with the states at which two particles are prepared in when they're ...
Pressure on sensor4/30/2009
  Q: Steve, You are stubborn! I understand you don't want to do students' homework, given to them from ...
  A: I'm not stubborn, and I answered this question already if you read my entire answer. It depends on ...
UNIFIED THEORY-NOT A HOMEWORK4/30/2009
  Q: Q:Sir,why should we look for a unified force theory without knowing exactly whether the nature ...
  A: I think I accidentally clicked on homework rejection on your last question, sorry about that. If ...
HERF and man-made auroras4/30/2009
  Q: Steve, I am currently writing a bit of science fiction that I need help getting as accurate as ...
  A: It would not, though a large enough nuclear blast in the upper atmosphere might interact with power ...
HERF and man-made auroras4/29/2009
  Q: Steve, I am currently writing a bit of science fiction that I need help getting as accurate as ...
  A: Sure, here's an example of a man-made aurora: http://en.wikipedia.org/wiki/Starfish_Prime You can ...
physics4/29/2009
  Q: I have a couple of questions regarding physics. The first one might seem silly to a physics ...
  A: E=mc^2 gives you the equivalent conversion amount, but matter and energy are different. As energy ...
basketball4/29/2009
  Q: My homeowners association requires portable basketball goals be kept close to the house when not in ...
  A: How did you measure the angle? 25 degrees is rather steep for a driveway. Anyhow, the answer is ...
heat and sound4/29/2009
  Q: Please tell me how to detect heat by infrared rays and radius. I know that we can use thermal ...
  A: I'm not sure what you mean by thermal inductance. Or why you need a radius, the simple detection of ...
Travelling at speed of light4/28/2009
  Q: What is the meaning or the statement ' nothing can travel faster than the speed of light' ? If a ...
  A: The observers on Earth the spaceship behaving exactly as the laws of physics says it should. So do ...
Travelling at speed of light4/28/2009
  Q: What is the meaning or the statement ' nothing can travel faster than the speed of light' ? If a ...
  A: Its acceleration would change relative to observers on Earth, it would continue to observe the same ...
DIMENSIONS4/27/2009
  Q: Sir, I've 2 questions: 1. How is the weight and length of whales, sharks and other large sea ...
  A: 1) They're roughly neutrally bouyant, so their density is the same as sea water. Therefore, using ...
twin paradox4/27/2009
  Q: how is the twin paradox solved in which one of them travel in spaceship? b'coz in it both will ...
  A: By accelerating, he changes the inertial reference frame in which he exists. That causes his clock ...
basic pressure understanding - not home work4/27/2009
  Q: Steve, I know you don't answer homework. But I don't even go to school. I'm 40 this August. The ...
  A: It's a numbered list of questions about a specific diagram, and I still have no idea where these ...
physics4/26/2009
  Q: I have a couple of questions regarding physics. The first one might seem silly to a physics ...
  A: Angular momentum is like linear momentum, it's rotational inertia multiplied by angular velocity. ...
Generators4/26/2009
  Q: I have a question. i am constructing a generator in which the magnets attached to a metal rod are ...
  A: It'll be AC, the field will be flipping back and forth. Therefore the rate of change of the ...
voltage4/25/2009
  Q: Sir, Inspite of being an undergraduate student in electronic engineering, i am not clear in the ...
  A: Electrical current flows because there's a net electric potential difference between the two ...
plank time4/24/2009
  Q: plank time does this mean time is not continuous as there is gap in it , that is we actually ...
  A: It's spelled Planck, as in the last name of German physicist Max Planck. ...
evaporation4/24/2009
  Q: how does water evaporate when kept outside below 100°c, i know it starts evaporating at 100°c only ...
  A: Even fractional distillation doesn't completely separate a mixture, it only alters the balance of ...
work or force to compress air4/24/2009
  Q: I was thinking of making a fire piston (small fire starting device that compressed air in a ...
  A: Fire tubes are fun, but break easily so be careful in the actual use. No heat is exchanged with the ...
My science fair project.4/24/2009
  Q: Do you know anything about model rockets? How do you use them? How do you make them and launch them? ...
  A: There's enough information in my profile for you to go to the school in my details and look me up ...
My science fair project.4/24/2009
  Q: Do you know anything about model rockets? How do you use them? How do you make them and launch them? ...
  A: As a science fair director and physics professor, I can tell you that it would be a good science ...
understanding the physics of a balloon rocket and also a paper rocket4/23/2009
  Q: Nelson, my daughter is a Sophmore in High School and has to present these two demonstrations to her ...
  A: I'm not sure which type of paper rocket you mean, most of them seem to act more like guns than ...
Observing jet contrails - earth rotation4/23/2009
  Q: Should a jet's contrail (flying from the south to the north) remain in the same part of the sky ...
  A: Ahh, good question and a tricky visualization. Not a curl, the plane is in the air. Relative to ...
My science fair project.4/23/2009
  Q: Do you know anything about model rockets? How do you use them? How do you make them and launch them? ...
  A: Are you talking about the type of rocket with snap-out wings that deploy at the end of its flight, ...
gravity4/23/2009
  Q: i understand motion of object/planet orbiting curved space created due to the presence of mass but ...
  A: More to the point, how can an object which isn't moving at all be attracted to the Earth? The ...
Question about General Relativity4/23/2009
  Q: I'm an amateur at physics, but am interested in the experiments that set gravitation as the bending ...
  A: To your questions: 1) Newtonian gravitation doesn't really predict the bending of light, because ...
time and objects speeding from earth4/22/2009
  Q: Five years ago my high school science teacher showed the class an older video from I think the ...
  A: Ummm...you may have seen who you consider a "hippie" scientist present something in a film five ...
Observing jet contrails - earth rotation4/22/2009
  Q: Should a jet's contrail (flying from the south to the north) remain in the same part of the sky ...
  A: No, as wide as it looks from the ground, the part of the sky you can actually observe is shockingly ...
GRAVITATION4/22/2009
  Q: Q.sir,i came to know that a body will execute a simple harmonic motion when it goes into a tunnel ...
  A: Symmetry. It turns out that if you're inside a spherical shell of mass the gravitation is pulling ...
My science fair project.4/22/2009
  Q: Do you know anything about model rockets? How do you use them? How do you make them and launch them?
  A: I know lots about model rockets, what do you want to know? Typically you follow a kit and launch ...
expantion coefficient4/20/2009
  Q: i want to know what is the basic agent affects the expantion coefficient of gallium or mercury in ...
  A: This is a straight-up thermodynamics problem. There will be Gibbs free energy terms related to the ...
expantion coefficient4/20/2009
  Q: i want to know what is the basic agent affects the expantion coefficient of gallium or mercury in ...
  A: I'm confused, largely because a grammatical glitch in this sentence left me wondering exactly what ...
evaporation4/20/2009
  Q: how does water evaporate when kept outside below 100°c, i know it starts evaporating at 100°c only ...
  A: Molecules evaporate from water at every temperature. Molecules will even come off of ice (it's ...
Falling Car4/20/2009
  Q: A buddy and I were watching Mythbusters when a car was dropped 400 feet. The engine (front)part of ...
  A: You're both right and wrong, that's how these arguments almost always go. Air resistance provides ...
evaporation4/19/2009
  Q: how does water evaporate when kept outside below 100°c, i know it starts evaporating at 100°c only
  A: No, 100 degrees Celsius is just where the vapor pressure exceeds atmospheric pressure, allowing the ...
Sound4/18/2009
  Q: Is there a simple and possible way to make a device that enables a human to hear sounds emitted by ...
  A: You'd have to make the elephants breathe the helium or the bats breathe xenon/argon to make the ...
physics4/18/2009
  Q: why we use convex lens of small focal length for a magnifying glass?
  A: I won't drag you through the optics of it, but the magnification of a simple magnifier is given by ...
coulomb force4/15/2009
  Q: can a charged body exert coulomb force on a neutral body?
  A: Yes, generally a charged body will polarize a neutral body. The opposite charges will be pulled ...
gaussian distribution4/14/2009
  Q: i am studying the statistical distribution of the size of crystals formed in a cement clinker. i ...
  A: I'd say it's a binning issue, but it's the wrong distribution for it. That brings us back to ...
Question4/12/2009
  Q: Help me with this question please. In capillary pipe why water uprise until it arrive higher than ...
  A: Surface tension. See this picture: ...
Shockwaves4/11/2009
  Q: Do you know what the density increase in a shock wave through a mix of liquid lithium and lead is? ...
  A: It's going to depend on many factors that you'll need to specify in a follow-up for me if I can ...
Sound4/10/2009
  Q: i am in graduate.Does our singing really sound better in a shower? If so,What are the physical ...
  A: I can't answer "better" or "worse" because that may depend on personal taste. However, resonant ...
Sound4/10/2009
  Q: i am in graduate.I want to ask that Sound wave can be used to measure the speed at which blood flows ...
  A: Sound reflects off of the red blood cells in the arteries and veins. It acquires a Doppler shift ...
vapor pressure4/10/2009
  Q: When a liquid is placed in an evacuated container,at constant pressure some of the liquid molecules ...
  A: No, they don't completely occupy the space. In fact, they occupy very little of the space, really, ...
Gas turbine working4/10/2009
  Q: I have a small doubt..what is the feasibility of using a gas turbine engine in atmospheres that ...
  A: Depends on the design. Generally you want high masses in the flow to get momentum transfer. ...
Electrostatics4/9/2009
  Q: Sir, My question is (i)why the electric field inside a charged conductor is zero? (ii) Why do the ...
  A: Inside a conductor, charges are free to move. If any field exists briefly in a conductor, the ...
Gravity and the theory of everything4/9/2009
  Q: (this may be a loaded question) Do you think gravityis a pulling effect/phenomenon or a pushing ...
  A: The genius of Einstein's General Relativity is that it turned the scientific community's thinking on ...
x-rays24/8/2009
  Q: can you give me some examples of x-ray radiation please?
  A: X-rays are usually generated by stopping high-energy electrons, like the high-energy electrons in a ...
x-rays4/8/2009
  Q: can you give me any details on the frequency of x-rays?
  A: No need, you can calculate it for yourself. Just divide the speed of light by the wavelength. ...
absoluteness4/8/2009
  Q: einstein in his relativity has said that everything is relative , because there is no ...
  A: The universe is the very extent of space itself. It has no center. It's more complex to think ...
Gas turbine working4/8/2009
  Q: I have a small doubt..what is the feasibility of using a gas turbine engine in atmospheres that ...
  A: Ahh, so you're adding the oxidizer in the turbine in the same place you add the fuel. This should ...
car crash, vehicle in motion hitting stationary vehicle4/6/2009
  Q: Scenario of car crash: I pulled up to a stop sign intersection facing east at the same time as ...
  A: Let me go straight to your questions. No, the moving car will not generally inflict more damage. ...
simple harmonic motion4/6/2009
  Q: hallo, I'm asp & seek help regarding spring mass system let us assume initially there is spring ...
  A: The sum of forces is equal to mass*acceleration. I don't use the term "inertia force," so we're ...
Gas turbine working4/6/2009
  Q: I have a small doubt..what is the feasibility of using a gas turbine engine in atmospheres that ...
  A: I'm pretty sure methane and nitrogen don't combust. You need fuel and an oxidizer, that's where ...
physics of still water (in white water rapids)4/3/2009
  Q: I need a simple way to explain still waters that appear in streams that also include white water. ...
  A: The water isn't really still, it's just moving very slowly. It's based on geometry. Rapids occur ...
physics4/3/2009
  Q: Are electrons and negative charge the same things or not.please explain your answer
  A: No, electrons are particles. They have a property called charge, just like they have a definite ...
coil voltage & rate change4/3/2009
  Q: I am slightly confused over a coils flux and rate change. If I impress a flux of 100A/uS into a ...
  A: I don't see anywhere that he explains DVDI still. I'll need more full information on what you do ...
physics4/3/2009
  Q: I am feeling really puzzled about the difference between resistance and resistivity.please explain ...
  A: Resistance is the resistance to flow of electricity through an object. That object is made of a ...
coil voltage & rate change4/2/2009
  Q: I am slightly confused over a coils flux and rate change. If I impress a flux of 100A/uS into a ...
  A: We have some bad terminology here you'll need to clear up in a follow-up before we can continue. ...
"physics for dummies:" resonance in matter4/2/2009
  Q: I am currently researching the properties of stone, rocks, crystals and other matter that act as ...
  A: Perhaps you could clarify what you mean by "response." In general, no, sound frequencies do not ...
n s pole4/2/2009
  Q: which is the pole of a magnetic compass that get deflect near to the wire carrying dc current and ...
  A: Depends on the direction of the DC current. The compass will want to line up perpendicular to a ...
Motor4/2/2009
  Q: I have a question concerning how an electric motor works. I took apart a working garage door opener ...
  A: It's probably not the right type with permanent magnets, so it probably won't produce a lot of ...
Motor4/1/2009
  Q: I have a question concerning how an electric motor works. I took apart a working garage door opener ...
  A: You REALLY need to study up on AC vs DC and circuits in general to even come close to doing this and ...
gravitation4/1/2009
  Q: If in a room filled with air(uniformly), there are 2 spherical cavities some distance apart, what ...
  A: If you're holding back the air from the empty cavities with physical shells that have mass, those ...
gravitation3/31/2009
  Q: If in a room filled with air(uniformly), there are 2 spherical cavities some distance apart, what ...
  A: Depends on the mass of the cavities, you need something to hold the air back. Let's assume they're ...
hydro-turbines3/30/2009
  Q: Steve,i am working on putting a hydro-turbine in a closed loop system..the non potable water ...
  A: I don't have an option to change the status of an answered question from public to private, that ...
hydro-turbines3/30/2009
  Q: Steve,i am working on putting a hydro-turbine in a closed loop system..the non potable water ...
  A: I'm a little unsure about the overall purpose of your system, perhaps you could follow-up with an ...
Quantum phenomenon3/30/2009
  Q: My husband and I need to resolve a friendly argument: IS THIS A THEORETICAL POSTULATE OR IS IT AN ...
  A: Changing charge? Charges don't just change. What you describe is mildly similar to the quantum ...
Volume of water change with temperature3/29/2009
  Q: How do i design a laboratory experiment to investigate how the volume of a given amount of water ...
  A: If you don't like dong experiments, why did you ask me to help design an experiment you could do ...
ufo3/29/2009
  Q: I have a rather hard to explain question, but I will try my best. Years ago i saw a very ...
  A: It would help if I had a picture, but the colors you mention all appear in the nitrogen emission ...
physics3/28/2009
  Q: I was wondering if you could explain this better for me, A 4kg mas and a 10kg mass are acted on by ...
  A: No, that's not right. If they're acted on by the same force, then the 10 kg mass will experience an ...
Sound3/27/2009
  Q: Why sugar syrup containing bottle produces fizzy sound while opening cap?
  A: There's either extra air pressure inside or too little (temperature change could cause this) and as ...
Design experiment3/27/2009
  Q: How do i design a laboratory experiment to investigate how the current which passes between two ...
  A: This guy has done a lot of research on the practical issues: ...
a question about how to clean glass plate3/27/2009
  Q: i am going to do some research on the contact angle between glass plate and water. firstly, i think ...
  A: I'll tell you what I do know, but this is getting outside of my area of expertise, you probably ...
Water defying gravity?3/26/2009
  Q: White-water rafting is a wet sport because the swift water flowing over the rapids, enters the still ...
  A: Energy density. All the terms in Bernoulli's equation are in units of pressure, which is equivalent ...
Light3/26/2009
  Q: If you had two objects in orbit, say like the moon and the earth. Then for some impossible reason ...
  A: No, because seeing them would require light to reflect from the surface on the side facing the ...
newton's first law3/25/2009
  Q: Can you help me understand newton's law of interia at general and specially in on its role of the ...
  A: That law is very simple, it just states that an object which is moving will continue to do so until ...
light3/25/2009
  Q: what is the weight of a light ray?
  A: Light has no mass. It contains energy equivalent to mass (E=mc^2), but it has no mass itself. ...
microwave oven3/25/2009
  Q: why metallic vessels are not suitable in microwave oven?
  A: Microwaves are designed to contain microwave photons as standing waves reflected between their ...
Electric sharge3/25/2009
  Q: I have two question,hope you will satified me.I have done graduate in physics. Q1)Why do ...
  A: 1) They involve high voltages generated by very small charges. That means that water molecules are ...
a question about how to clean glass plate3/24/2009
  Q: i am going to do some research on the contact angle between glass plate and water. firstly, i think ...
  A: Solvents work well for basic cleaning (windex, etc). The only way to get rid of extra molecules ...
classical physics3/24/2009
  Q: I read somewhere in Wikipedia that Classical physics is Superseded by relativistic and quantum ...
  A: There's currently no way to know, actually. We know that at some level they can't both be right, ...
the space between atoms3/23/2009
  Q: On the atomic level, there is some free space between the electrons and nucleus of atoms (and ...
  A: Actually, there isn't. That's the classical notion of the atom, but quantum mechanics has shown us ...
classical physics3/23/2009
  Q: I read somewhere in Wikipedia that Classical physics is Superseded by relativistic and quantum ...
  A: Classical physics is, in fact, an approximation of relativistic physics and quantum mechanics. That ...
pressure?3/23/2009
  Q: Steve, thanks for answering my first question. Now leading on from that....this link asks the next ...
  A: First you added pressure from some unknown source to the bottom bottle. But that bottle still has ...
force & elasticity3/23/2009
  Q: Does elasticity depend on mass? I used two objects of similar volume (metal ball and ping pong ...
  A: Elasticity is a material property, not dependent on mass. It's a material property. What did you ...
pressure?3/22/2009
  Q: Question for you, please. If I increase the air pressure in bottle A will it force the water from ...
  A: Yep. You may find you have to increase that pressure a lot. First you have to increase it enough ...
displacement in S.H.M after the periodic time3/22/2009
  Q: I was trying to find a law that i can calculate periodic time with displacement and i tried this: ...
  A: You can't calculate periodic time based on displacement. It's the same time for simple harmonic ...
resistance3/22/2009
  Q: The cross section of a portion of wire increases uniformly so it has the shape of a truncated cone. ...
  A: To "integrate" means to add together. You add resistors in series, so integrate along its length. ...
friction3/20/2009
  Q: My question is: I have a block 1800 lbs on a surface with friction coefficient of .8 . I have an ...
  A: Since you approach this with an attempted solution, I won't reject this as a homework question out ...
Energy production3/19/2009
  Q: If a hollow tube were to be lowered to a sufficient depth in the ocean,would the greater pressure at ...
  A: Absolutely not, you'd have to force the pipes down below the surface of the water, fighting the ...
Aerodynamics3/19/2009
  Q: I'm doing a presentation on aerodynamics in my physics class, and I was just wondering if you could ...
  A: Bernoulli's equation. In flight, the shape of the wing forces the air to move faster over the top ...
negative ions3/19/2009
  Q: Do negative ions produced in some air purifiers create ozone that is unsafe?
  A: Apparently so. I'll refer you to the below link from the experts from the State of California. ...
expansion of water on freezing3/18/2009
  Q: I have a small quarry on my property, filled with water. It is a confined basin, about one acre in ...
  A: I'm slightly confused by the phrasing of the question, so perhaps you can clarify. Separation ...
Water pressure3/18/2009
  Q: I am sending you this question because you are willing to deal with "everyday observations of ...
  A: I'm not actually talking about things on a microscopic level, the gaskets in valves give quite a bit ...
Wave propagation3/18/2009
  Q: Would you be so kind to explain me what wave propagation is? Thanks in advance, Bas
  A: Wave propagation is just a general science term. It means the traveling of a wave, or the method of ...
reflection3/18/2009
  Q: A street light,viewed by reflection across a body of water in which there are ripples,appears very ...
  A: Well, that depends on the direction and size of the ripples. If the ripples are headed towards or ...
Gravity3/17/2009
  Q: Is gravity a particle or a wave ?. If it's a particle can it be detected,and if it's a wave do we ...
  A: Gravity is a distortion in spacetime. It's generated by the presence of matter and energy. ...
Water pressure3/17/2009
  Q: I am sending you this question because you are willing to deal with "everyday observations of ...
  A: I'm having to figure this out by thinking in detail about the system, but I believe I have an ...
help on DDP project3/17/2009
  Q: I'm sure you probably get many many people asking you about the same project so I'm sorry if it ...
  A: Packing peanuts are allowed? You could simply glue them to the outside. Alternatively, taking a ...
force of impact on a multi car collision3/16/2009
  Q: This is not a homework discussion. I am having an agrument with a friend of mine and I just wanted ...
  A: The answer is complex and depends on what you want to really know: the force between the cars or ...
engineer fair project!!!!! HELP ME!!!!!3/16/2009
  Q: I'm doing a project for school(required),and have no idea how to build a rubber band powered car!!!! ...
  A: In this case, there are several factors. 1) Make it as light as possible, but still stable. ...
momentum3/14/2009
  Q: sir which will be more effective in knocking down a bear down. i- a rubber bullet ii- a lead bullet ...
  A: A rubber bullet, based on conservation of momentum. The bullet bounces, therefore has a greater ...
electrostatic force3/14/2009
  Q: Can you please help me with question 13 and Numerical respons 7 on this site: ...
  A: 13 is just a vector problem, basically the Phythagorean theorem. You square and add the two ...
Water Freezing Above 32 F.3/13/2009
  Q: Steve, I have a co-worker who has started a few acres of organic blue berries. He asked me if I ...
  A: No. You can temporarily superheat formed ice crystals a little in the lab by raising their pressure ...
radioactivity3/13/2009
  Q: I am interested in using Uranium glass that was produced pre 1940's in my artwork, making light ...
  A: It should be fine. The material will contain very very tiny amounts of radon, which is chemically ...
Heat3/13/2009
  Q: What is the difference between specific heat and heat capacity?
  A: They're related. Heat capacity is often used to mean specific heat, but heat capacity refers to a ...
Fluid temperatures3/12/2009
  Q: Hot or warm air is lighter than cooler air, and thus rises. I always believed that water behaved ...
  A: It would only cool rapidly to the same temperature if stirred. Convection is an exceedingly slow ...
Fluid temperatures3/12/2009
  Q: Hot or warm air is lighter than cooler air, and thus rises. I always believed that water behaved ...
  A: Depends on geometry and time. Several geometric temperature factors, the first one is the straw. ...
surface tension3/11/2009
  Q: Please can you tell why does surface tension of liquids fall with temperature?
  A: You can picture it this way: at lower temperatures molecules slow down, allowing the attractive ...
heat3/11/2009
  Q: why are mountain tops cold?
  A: Temperature drops as pressure drops in the atmosphere. This is known as the environmental lapse ...
Physics3/11/2009
  Q: What is negative energy? When can the total energy of a system be 0? If total energy is 0, can it be ...
  A: There's no such thing as "negative energy." You can mathematically define a negative potential ...
Particle Accelerators3/10/2009
  Q: I'm an 18 year-old student studying my A-Levels in Britain. I love physics. I was wondering: is it ...
  A: Having been involved in the construction and maintenance of low-energy accelerators before, I can ...
circular motion3/9/2009
  Q: what is tangent
  A: A tangent is a straight line perpendicular to the radius of a circle and touching the circle in ...
question3/9/2009
  Q: what is the difference between first order and second order phase transmortion? how should we ...
  A: A first order phase transformation, like the boiling of water, involves a latent heat. It either ...
physics3/9/2009
  Q: what will happen to a car that is travelling at 50 kilometers per hour if a large force is applied ...
  A: That depends on the magnitude and direction of the force. If the force is applied to the rear of ...
Physics2/26/2009
  Q: In semiconductors, for intrinsic carrier concentration, how the probability function f(E)is ...
  A: It's been a while since I've had solid state physics, myself, and the scope of your question goes to ...
Is it a wheel?2/25/2009
  Q: Nelson, In class we are learning about wheels. We have a question. Is a top a wheel? 14 of us ...
  A: In my opinion, no. A wheel is a device designed to support weight while rolling without slipping, ...
kinetic and potential energy2/25/2009
  Q: Is it possible for a human to have both zero potential and kinetic energy. If potential energy is ...
  A: First, the absolute value of potential energy is arbitrary, so it's technically possible to just ...
Wind chill effect2/24/2009
  Q: I need an answer to settle a friendly argument, and I think it's a physics question. If the wind is ...
  A: Of course for your second example that would eliminate the wind and therefore the wind chill. For ...
complex variables2/23/2009
  Q: i don't understand what a complex variable indicate?.Does it refers to a single point or more.what ...
  A: Complex variables are mathematical constructs with specific properties, much like matrices or ...
pressure2/23/2009
  Q: i'm a B-pharm-1 student.my doubt is how inter molecular forces of attractions can accounts for ...
  A: No, think about the equation. Look at the other side of the equation. That is constant, like 1 ...
pressure2/22/2009
  Q: i'm a B-pharm-1 student.my doubt is how inter molecular forces of attractions can accounts for ...
  A: That's not an increase in pressure, it's a decrease. The pressure added to a constant, in that ...
pressure2/22/2009
  Q: i'm a B-pharm-1 student.my doubt is how inter molecular forces of attractions can accounts for ...
  A: They don't cause pressure at all. Pressure is caused by molecular collisions with the container ...
hi2/21/2009
  Q: When we float, we can’t do things we normally do on Earth’s surface that scientists think of a way ...
  A: The acceleration of Earth's gravity is 9.8 m/s^2. The centripetal acceleration due to rotation is ...
Kinetic Energy2/21/2009
  Q: I have some doubts as to the application of kinetic energy in some circumstances, the main one being ...
  A: You use a slightly complicated situation as an example, but your math is correct. If I was riding ...
elementary physics2/20/2009
  Q: When you roll an aluminum can using a balloon and static electricity How fast will it roll? How far ...
  A: Static electricity generally exerts weak forces, because significant static electricity buildup is ...
Lifting to weight ratio2/20/2009
  Q: How much weight will one square foot of a vacuum lift? ANSWER: You technically mean how much weight ...
  A: Oh, that's very different and you need to pose the question in cubic feet, not square feet. The ...
Lifting to weight ratio2/20/2009
  Q: How much weight will one square foot of a vacuum lift?
  A: You technically mean how much weight will one atmosphere of pressure lift when applied to the bottom ...
acoustics2/20/2009
  Q: A man-sized object breaks the sound barrier at 10,000 feet. Would the boom be loud enough to notice ...
  A: It's most likely between 50,000 and 100,000 ft where you drop from about 10% atmospheric pressure to ...
Science Fair Project - Ice2/20/2009
  Q: My son wants to do a science fair project with regard to ice. Any suggestions as to a good project ...
  A: Many! I'm the director of the regional science fair (where the local fair winners go before the ...
physics2/19/2009
  Q: what is a light gate?
  A: Well, there are two things you could be referring to. One would be a photogate, which is a ...
acoustics2/19/2009
  Q: A man-sized object breaks the sound barrier at 10,000 feet. Would the boom be loud enough to notice ...
  A: A sonic boom is a set of types of cone-shaped shock-wave that builds up just as an object reaches ...
electricty being produced2/19/2009
  Q: i need you to help me to understand about electricity being produced. the only way i know is when ...
  A: This isn't quite correct. A change in magnetic field creates an electric field (Faraday's law). ...
force2/19/2009
  Q: I hang a block by a string from a strong support & another sting from bottom of the block. Now, if I ...
  A: If you give it a fast jerk then no time is given for the mass of the block to accelerate and ...
finding research info2/18/2009
  Q: I am doing a science experiment and I am having a hard time finding research info on the topic. Can ...
  A: This is a good question, but hard to answer because the answer depends on so many things. Mostly ...
history of maths/physics2/17/2009
  Q: I recall reading an aside issue in abook about electromagnetism that the derivation of E=mc^2 had ...
  A: You have to understand when you read these stories, people are obsessed with Einstein. His name is ...
Rotation mystery.???2/11/2009
  Q: .. Below is a link that shows a blond Russian lady Hammer thrower (ther are about 4 other ...
  A: This problem is not a great mystery if you're only considering angular momentum, and certainly ...
stainless steel weight2/11/2009
  Q: I have a question about the weight of stainless steel. I want to know,that, what will be the weight ...
  A: Sure, you need to know the density of the steel. Stainless has a density of 8000 kg/m^3, while ...
physics2/11/2009
  Q: How does friction relate to something falling 5.5 meters with a parachute? ANSWER: Why 5.5 m? Why ...
  A: You're interested in drag forces for an egg drop, why didn't you say so? Just deal with drag ...
physics2/10/2009
  Q: How does friction relate to something falling 5.5 meters with a parachute? ANSWER: Why 5.5 m? Why ...
  A: No, though drag forces are in some ways similar to friction. They resist motion, but drag forces ...
physics2/10/2009
  Q: How does friction relate to something falling 5.5 meters with a parachute?
  A: Why 5.5 m? Why not 6 or 60? It's all the same when you're talking about a parachute once you've ...
Gravity2/10/2009
  Q: I have a weird question for ya. I know that magnetic fields and electric fields exhibit all of the ...
  A: At some point in studying physics, everyone wonders about this. No one has yet managed to unify ...
Rotation mystery.???2/10/2009
  Q: .. Below is a link that shows a blond Russian lady Hammer thrower (ther are about 4 other ...
  A: I can think of two things. Either her hands were moving in a direction perpendicular to the main ...
Energy Mechanics2/9/2009
  Q: If the acceleration of an object is not zero, can the velocity of the object be zero? and Also,... ...
  A: First question, yes. For example, if you throw an object up in the air it's always accelerating ...
light2/8/2009
  Q: If light is energy (photons) then why, if one wraps an LED in aluminum foil to reflect light back ...
  A: Heat, LEDs use very very little power. If you want a better example of energy being converted into ...
light2/7/2009
  Q: If light is energy (photons) then why, if one wraps an LED in aluminum foil to reflect light back ...
  A: They wouldn't reflect off the LED well at all, and the aluminum foil isn't 100% reflective. There's ...
capacitance and change in charge, voltage2/7/2009
  Q: I am having trouble understanding capacitance, since each physics source I read gives a different ...
  A: Voltage doesn't change the capacitance. Capacitance results from the geometry of the conductors. ...
brrnoulii2/7/2009
  Q: In the steady flow, what is the factor that decreased the pressure and increased the velocity when ...
  A: The question is posed in a confusing fashion, but let me explain what Bernoulli's equation really ...
question2/6/2009
  Q: what is space time co ordinate?
  A: Much like standard three-dimensional coordinates, a space time coordinate is a set of three spatial ...
Desalinating the Ocean2/6/2009
  Q: I am a senior at my school and am taking an independent physics class in which I explore areas of ...
  A: I have an idea or two for this, actually, but it's a bit outside my field as I'm a nuclear physicist ...
Desalinating the Ocean2/5/2009
  Q: I am a senior at my school and am taking an independent physics class in which I explore areas of ...
  A: Reverse osmosis (RO) is the main form. It requires putting pressure across very large areas of ...
physics2/3/2009
  Q: can u tell me if thier is a maximum speed that somthing can fall at, an if thier is wot speed is it? ...
  A: The speed of light comes to mind, of course. Actually the speed you were quoted is about the speed ...
Newton's 2nd Law2/3/2009
  Q: Recently I was tobogganing with my little brother. After racing to the bottom of the hill (which I ...
  A: In the classroom physics world, you're right. Absolutely it should make no difference between you ...
electric and magnetic field2/3/2009
  Q: isn't a magnetic field created by a magnet(or a dipole) similar to a field created by a +ve and a ...
  A: They're related via Maxwell's equations, which provide a mathematical description of the laws of ...
ice breaking2/3/2009
  Q: Is it possible to shatter ice (on a driveway/sidewalk or roof of house) using microwave or ...
  A: The short answer is yes, but the immediate thing that occurs to me is that either would be ...
Magnetic Field2/2/2009
  Q: I always thought magnetic lines of force eminate from a north pole and entered a south pole. a wire ...
  A: Magnetic field lines are closed loops, always. They run back from south to north poles inside the ...
buzzing sound in the house2/2/2009
  Q: We have a constant buzzing sound which resonates throughout the house even when power cut off. ...
  A: These are tricky, I get these a lot. The trouble with resonating sounds is that they're difficult ...
Friction and force2/1/2009
  Q: I am trying to figure out why it takes so much force to separate two phone books that have been ...
  A: There's a certain frictional force per page when they're all clamped together, which depends on the ...
electric and magnetic field1/31/2009
  Q: isn't a magnetic field created by a magnet(or a dipole) similar to a field created by a +ve and a ...
  A: Well, it's far more complex than that. Here's a few things for you: Excess of electric charges of ...
cosmology1/30/2009
  Q: not sure that the following is your area but il try! I have a very keen,amateur interest in ...
  A: Let me try to run through this and then re-direct you to a much more informative source for the ...
cosmology1/29/2009
  Q: not sure that the following is your area but il try! I have a very keen,amateur interest in ...
  A: Ack! You need a full course in General Relativity, it's a very complex subject and you've waved ...
DC Motors1/29/2009
  Q: What if any damage would occur to a 12V DC Motor if the polarity is reversed? This would be a small ...
  A: Hobbyists reverse the polarity on DC motors all the time to make them run in reverse, as I ...
Sub-atomic physics1/29/2009
  Q: If you were planning to energize an atom to a higher energy state what would the best method to do ...
  A: After this many follow-ups, you really need to just go read up on the subject by doing some research ...
Sub-atomic physics1/29/2009
  Q: Is it known what causes radioisotopes disintegrate spontaneously. What i mean by the above question ...
  A: My advisor in grad school wrote a definitive paper on this while I was at Duke. I could only find ...
Sub-atomic physics1/28/2009
  Q: Is it known what causes radioisotopes disintegrate spontaneously. What i mean by the above question ...
  A: That's its ground state, isotopes with long-lived metastable states are rare. 137Cs doesn't have ...
Sub-atomic physics1/28/2009
  Q: Is it known what causes radioisotopes disintegrate spontaneously. What i mean by the above question ...
  A: If that was your question, you could've asked right away. I do teach how to calculate decay rates. ...
Sub-atomic physics1/28/2009
  Q: Do the protons and neutrons in a nucleus vibrate. ANSWER: It's part of a model of the nucleus (we ...
  A: No, the strength of the force doesn't vary between nucleons. But it is short range so it only acts ...
physics tatto help....:)1/28/2009
  Q: i was hoping you could help me with a tatto design i already have the fourier transform on one arm i ...
  A: I'll have to think about this, so I may follow up with another answer. The first things that come ...
Sub-atomic physics1/28/2009
  Q: Do the protons and neutrons in a nucleus vibrate. ANSWER: It's part of a model of the nucleus (we ...
  A: The strength of the strong nuclear force doesn't depend on which isotope it's in. It's 137 times ...
Sub-atomic physics1/28/2009
  Q: Do the protons and neutrons in a nucleus vibrate.
  A: It's part of a model of the nucleus (we have no exact formulae for the strong nuclear force, they're ...
another question...1/28/2009
  Q: it was silly, I guess there was something I misread, so I'm sorry about wasting your time, but I ...
  A: Well, four dimensions are all we observe. And as far as time "accelerating," you're referencing ...
another question...1/27/2009
  Q: it was silly, I guess there was something I misread, so I'm sorry about wasting your time, but I ...
  A: Not silly, just a bit inverted. Anyhow, we measure the physical second in terms of oscillations of ...
I'm not sure, that's what I wanted to know1/27/2009
  Q: If something was standing entirely still, with a velocity of zero, would it be two dimensional? Is ...
  A: Ummm...you've got it slightly backwards both from a relativity standpoint and a quantum mechanics ...
Physics1/27/2009
  Q: My son is doing a science project on how far a water balloon can be thrown before it breaks. My ...
  A: The physics of breaking the balloon involves the breaking strain of a highly elastic material. The ...
ceramic paint additive for heat reflection1/23/2009
  Q: I purchaced a ceramic paint additive which is supposed to reflect heat back into the heated space of ...
  A: I did some research, and found that your laser thermometer may indeed be being affected by the paint ...
ceramic paint additive for heat reflection1/22/2009
  Q: I purchaced a ceramic paint additive which is supposed to reflect heat back into the heated space of ...
  A: Paint is thin, it's not going to do much at all. Your laser thermometer measures the temperature of ...
Regarding atoms1/22/2009
  Q: Has a proton, electron or an atom had ever been seen individually? We say that proton and neutron ...
  A: Yes, we have, on all counts. We image atoms with many types of advanced microscopes (atomic force, ...
production of electricity1/22/2009
  Q: Is there any process to produce electricity only by permanent magnet? I mean to say the production ...
  A: Nope, nothing I know of except to produce uncontrolled eddy currents. Those would be channelled ...
physics1/22/2009
  Q: My six year old son who is very into math and science is playing in the tub with a plastic drinking ...
  A: Yes, cohesion. Water is a polar molecule, the water molecules tend to line up next to other water ...
Sonic Boom1/15/2009
  Q: Could you please give me an idea of a science experiment that I could use for my sonic boom topic? ...
  A: To make a winning science fair project, your project should answer some kind of question. The only ...
Surface Tension1/15/2009
  Q: We know that mercury does not wet glass. Is there any material which is wetted by mercury?
  A: You would expect it to wet materials with similar chemical makeup, like another metal. Here's an ...
potential1/14/2009
  Q: why there is no acceleration when we transfer a charge from point a to point b in an electrostatic ...
  A: You set balanced forces as a condition in the initial problem, the result of which is an ...
Neutron hole1/14/2009
  Q: whilst reaserching CERN, I came across this site.Please take a look at it : ...
  A: I've read many of these websites, all of which are pure scare-mongering. Not only that, but the ...
Floating motorcycles across rivers1/14/2009
  Q: I am a Physics end user, but don't understand the process of figuring things out. I work and travel ...
  A: Is that the inner diameter, the outer diameter (which I will assume for this calculation), or the ...
Floating motorcycles across rivers1/13/2009
  Q: I am a Physics end user, but don't understand the process of figuring things out. I work and travel ...
  A: Archimedes' principle, you need to displace a weight of water equal to the weight of your gear. So ...
Gamma Rays1/12/2009
  Q: Hey, Goodnite. I was wondering if there was a specific range of frequencies from which Gamma Rays ...
  A: All x rays and gamma rays cause damage to cells. They're higher in energy than UV light, which also ...
Solar energy1/12/2009
  Q: Yes it is a 40 watt going to a 120v house current.Although i could try and find a smaller one if it ...
  A: Just google search "40 watt solar panel" and you'll find plenty of them. They all put out about 17 ...
earth's rotation1/12/2009
  Q: Sir- How much, if any, effect does the re-distribution of mass on the earths surface effect the ...
  A: No, the amount of mass that human activity shifts is absolutely tiny in comparison to the mass of ...
Freeze Drying1/11/2009
  Q: why is freeze-dried food mostly undamaged when defrosted?
  A: Well, it is quite damaged, but not as badly as if it was just fozen. They don't leave the water in ...
Gamma Rays1/11/2009
  Q: Hey, Goodnite. I was wondering if there was a specific range of frequencies from which Gamma Rays ...
  A: Not really, though they pass through you more easily at higher energies they have more energy to ...
Force and Density1/10/2009
  Q: Steve, Hello, I am a father who is helping his son on a science project, and I need some guidance ...
  A: The density doesn't affect it so much, the molecular binding forces do. That's far more complex, ...
is there a hand held device to measure the speed of light?1/10/2009
  Q: Could you tell me if there is a hand held device that can measure the speed of light? I’m ...
  A: Since the speed of light in a substance depends directly on the index of refraction, you can just ...
A 50 MILE DEEP HOLE1/10/2009
  Q: Yes is it possible if there was A 50 mile deep crater in the ground, There was A person all the way ...
  A: No, 50 miles deep the temperature would be so hot they'd die first. It's not the helicopter flying ...
scifi question for children's book1/9/2009
  Q: I write mystery fiction books for middle-school aged children, and I hope this is an appropriate ...
  A: Well, magnetic disturbances are easy. A standard iron meteorite would cause that. Or the heat from ...
Physics Project1/9/2009
  Q: We are currently working on an egg drop project with limited supplies. We can use: 1 sheet computer ...
  A: Ahh, it's egg-drop time. If the sandwich bag is zip-lock, so you can fill it with air, I'd try to ...
Bremsstrahlung Radiation1/9/2009
  Q: My understanding is the Bremsstrahlung Radiation occurs when a charged particle velocity changes ...
  A: No, that wouldn't work. Bremsstrahlung radiation is emitted with a very low cross-section at such ...
egg drop project1/9/2009
  Q: I have to do my egg drop project in my physic class and I totally have no clue on how to do it. What ...
  A: You want something that will provide even force and is pretty long, but will stay upright when it ...
Observational Theory on the Atlantis from Stargate: Atlantis1/9/2009
  Q: Good evening, A question in a fan forum has come concerning the city of Atlantis as depicted in the ...
  A: Your list of questions all have the same answer, Archimedes' principle. The buoyant force of an ...
"Gravity" in a Hollow Sphere1/8/2009
  Q: I know that because of Newton's shell theorem, the gravitational force inside a hollow sphere is ...
  A: Not the way you're thinking, the geometry of the sphere prevents it. It's basic geometry, anything ...
"Gravity" in a Hollow Sphere1/8/2009
  Q: I know that because of Newton's shell theorem, the gravitational force inside a hollow sphere is ...
  A: Of course it would, just spin it and you'll get just the force you mentioned to cause centripedal ...
solar energy1/8/2009
  Q: How do you make a homemade solar panel to absorb the sun's energy?
  A: http://www.youtube.com/watch?v=qYeynLy6pj8 This shows how you can assemble them, but you aren't ...
Help!!!1/7/2009
  Q: I've been working on my science fair and i need to ask an expert in my field for my research. I can ...
  A: If that's your question, test it! That IS your science fair project. I'm not a biologist or an ...
potential energy1/7/2009
  Q: why we chosen the infinity as a Reference instead of the center of the earth in calculating the ...
  A: The choice is arbitrary, and meant for mathematical convenience. You can use the center of the Earth ...
maglev tech1/7/2009
  Q: i was wondering if you knew anything about maglev tech. because me and my group want to make a ...
  A: First, a few questions for clarification: What does the "ir" in "maglev car ir train" mean? You ...
Solar Energy1/7/2009
  Q: How can I electrically wire a solar panel to a light bulb to make it shine/work?
  A: Well, there are many ways this can be done. If you're trying to wire a small standard solar panel ...
Radiant Heat Shield1/7/2009
  Q: We have a ventless fireplace and in the nook above, we have placed our stereo equipment. The ...
  A: I don't have any information about the Thermo-Tec insulating mat because (I looked it up) they don't ...
Apparent weight of objects underwater and movement?1/7/2009
  Q: I am a keen angler and would like to ask for your help with understanding buoyancy, movement ...
  A: There's not a lot of difference in the actual total density of a fishing line. There are ...
The freezing of Ice1/6/2009
  Q: I may have made a mistake flooding mu backyard rink. I put down a plastic sheet and filled the rink ...
  A: No, ice is a pretty good insulator. It usually takes a lake a good four days or so to freeze. You ...
Apparent weight of objects underwater and movement?1/6/2009
  Q: I am a keen angler and would like to ask for your help with understanding buoyancy, movement ...
  A: If you want less resistance at the first bite, then having slack in the line would seem to be the ...
physics1/5/2009
  Q: ! can you help me choose the easiest physic investigatory project, without using expensive ...
  A: First, as a science fair director, I'd say to follow the links on our science fair website. My ...
Physics1/4/2009
  Q: Does temperature effect the speed of a falling object? ANSWER: Temperature of the object? No. ...
  A: You'd need a long drop from someplace really high up. And make sure that humidity didn't change. ...
Physics1/4/2009
  Q: Does temperature effect the speed of a falling object?
  A: Temperature of the object? No. Temperature of the air? Yes, it'll affect the viscosity of the ...
Special Relativity1/3/2009
  Q: I have some questions to ask. 1. Is it true that it takes an instant for light to travel any ...
  A: For the first one, by "an instant" I'll take it to mean zero time. That is what it takes, zero time ...
Several Questions12/24/2008
  Q: I hope you can answer the following: 1.Is work always a result of energy conversion? And what ...
  A: 1) No, work is not always the result of energy conversion. Example, your light bulb, where ...
upthrust12/19/2008
  Q: A man is in his boat and is floating on a still lake. he has some stones with him in the boat. If he ...
  A: The stones are more dense than water, so they will sink (I'm assuming he's not throwing pumice into ...
Help calculating torque12/19/2008
  Q: I'm working on a two-wheeled balancing robot, but am stuck and need help with calculating the torque ...
  A: So you've calculated the torque from gravity at the angle you want, now your motor has to be able to ...
Help calculating torque12/19/2008
  Q: I'm working on a two-wheeled balancing robot, but am stuck and need help with calculating the torque ...
  A: This project isn't going to be solved with simple equations, and you might want to find someone with ...
Help calculating torque12/18/2008
  Q: I'm working on a two-wheeled balancing robot, but am stuck and need help with calculating the torque ...
  A: Speed at which it moves does not relate directly to torque, acceleration does. The torque applied ...
Physics 11 Help12/18/2008
  Q: Why can gravitational potential energy be described as an arbitrary value?
  A: Only changes in potential energy matter. Where you start and where you end are the determining ...
special glasses12/17/2008
  Q: how can i see behind the things? for example i want to see if someone carrying a weapon behind his ...
  A: I think you mean through and not behind. For behind you just need a mirror to see around things. ...
Newton third law12/17/2008
  Q: I have a simple question but it is confusing for me. According to Newton's third law, For every ...
  A: There is an equal and opposite response. You are pushed back on by the stone that you throw. You ...
Ships on Water12/16/2008
  Q: I would like to know how ships can sail in water. I read that the Ships are constructued in such a ...
  A: Archimedes, the ancient Greek philosopher and scientist, discovered the principle that the buoyant ...
rotational mechanics12/16/2008
  Q: Sir, I asked you the following question. When a screw is rotated on a flat surface, it slows down. ...
  A: Ahhh, now I understand! Rotating a screw is usually done to insert it into wood, so I was ...
surface tension12/16/2008
  Q: Two hollow glass spheres contain a little water & mercury respectively.What will happen when the 2 ...
  A: The liquids will want to form spheres inside the spheres. The mercury will do a better job of this, ...
Spring12/15/2008
  Q: I have a problem and I can not solve it. We have a simple spring.We compress it and fix the current ...
  A: The answer you provide is correct indeed. The non-compressed spring will not spring open and stir ...
tire rubber12/14/2008
  Q: The question has come up here about what happens to all the rubber wearing off all the cars on the ...
  A: All of it, in a sense, but it depends somewhat on the type of road. This is a little outside my ...
Physics12/14/2008
  Q: Hey... I'm having a problem on my Physics homework Oh and by the way, i really need this to be ...
  A: It's a bad question, there's no way that the motorcycle can clear the second block even at infinite ...
What is a "heterostructure"?12/13/2008
  Q: In http://www.allexperts.com/user.cgi?m=6&catID=1358&qID=4723397 you said that a "complex ...
  A: Heterostructures are not my area of expertise, but have many unusual optical and electronic ...
projectiles12/13/2008
  Q: I have been asked to find the angle that gives maximum projectile arc length , in horizontal ...
  A: Angle? Seems incompatible with the phrase "horizontal projectiles." I assume you meant projectiles ...
Sparks12/13/2008
  Q: How do atoms behave in different wall sockets and what makes different colored sparks?
  A: Well, contaminant atoms will alter which type of atoms in a spark are emitting light. For example, ...
Physics12/12/2008
  Q: Respected sir, I am Mukul of grade 11 The following question was asked to me by my teacher: Explain ...
  A: I don't answer homework questions. However, you should investigate here: ...
Thermal Infrared Fluorescent Lamps?12/11/2008
  Q: Most fluorescent lamps emit light in visible range. Is it possible to build a fluorescent lamp that ...
  A: For 1) a UV lamp emits very very little power. It only needs a fraction of the power of an ...
A rolling ball12/11/2008
  Q: What physical formulas and laws are applied to a spherical ball rolling on a flat surface. does ...
  A: As far as rolling friction goes, no. Static friction is what actually applies. The response force ...
Thermal Infrared Fluorescent Lamps?12/11/2008
  Q: Most fluorescent lamps emit light in visible range. Is it possible to build a fluorescent lamp that ...
  A: For 1) It'll have to get "hot" to emit infrared, that's basic physics. Even if you pump it with a ...
Heat and temperature12/9/2008
  Q: suppose an object is kept in bright sunlight, it will become warm depending upon time of exposure ...
  A: Energy has entered. First law of thermodynamics, in fact. What makes it feel warm? A flow of ...
Optics: Spectrometer12/9/2008
  Q: Sir, Why we use to focus the spectrometer for paraleel beams and what is the method of doing this?
  A: We need to focus them to parallel beams in order to separate the beams based on their different ...
Capacity and voltage ratio11/30/2008
  Q: If you have a metallic sphere (which has a fixed capacitance of course) and inside that sphere you ...
  A: No, within the inner capacitors you will retain the same *net* charge of zero. If you nullify the ...
Capacity and voltage ratio11/30/2008
  Q: If you have a metallic sphere (which has a fixed capacitance of course) and inside that sphere you ...
  A: A sphere has a fixed capacitance relative to matter at infinity. If you put spheres inside it you ...
kepler's laws11/29/2008
  Q: If you know the mass of a object that is emitting a gravitational field and the radius between it ...
  A: If it's in a circular orbit and you know the radius PRECISELY, then yes. You have a known mass M ...
Helium11/28/2008
  Q: Steve how far can Helium be compressed to? This is just a hypothetical example of numbers, but if it ...
  A: That balloon would be heavier, not lighter. Helium can be compressed to incredibly high pressure, ...
- egg drop-- conceptual questions11/27/2008
  Q: We have been asked to build a vehicle that would safely carry an egg from a height of fifty feet. ...
  A: It would be completely inelastic (maximum energy absorption in the crushing vehicle). Impulse is ...
billiards, kinetic energy11/26/2008
  Q: i an new and i need help with two questions. 1) In billiards(pool), is it possible for the cue ball, ...
  A: The first one is easy, of course it's possible. That's why the ball stops, it transfers all its ...
PHYSICS11/26/2008
  Q: We know 2+2 is 4, but can physics present a working model as to how a cell upon cenception becomes ...
  A: I won't ask who "they" are, you should just be aware that such a statement is a little vague. The ...
PHYSICS11/26/2008
  Q: Why does the ocean appear blue?
  A: This question has been answered well by others: ...
PHYSICS11/26/2008
  Q: We know 2+2 is 4, but can physics present a working model as to how a cell upon cenception becomes ...
  A: Matter is not created from less matter. The cells ingest organic matter (amino acids, proteins, ...
Special Theory of Relativity11/26/2008
  Q: It is said that Einstein in his teenage years, asked the question "what would I see in a mirror if I ...
  A: This question usually assume you're looking at a clock in the mirror. You may as well just look ...
object around the earth11/26/2008
  Q: I would like to know whether just as earth revolves around the Sun naturally, can we have an object ...
  A: It's called the Moon. As tempted as I was to leave that as my answer to your question, I feel like ...
INQUIRY11/25/2008
  Q: I m an engineer , unfortuntly after taking my bachelor degree I found that I unsatisfied with ...
  A: You wrote that you enjoyed puzzling out physics and mathematical problems. In modern industry this ...
einstein11/25/2008
  Q: my question is regarding the famous equation E=mc squared. I understand this to mean that each tiny ...
  A: They all have "mass," therefore they have the kind of energy you're talking about. But mass does ...
Wave Interference11/25/2008
  Q: I am doing a physics experiment,connecting two speakers to emit same sound frequency to produce node ...
  A: Easy, in theory. Make them out of phase by 180 degrees. So possibly difficult to delay the signal ...
Egg drop- energy conservation11/25/2008
  Q: how would you explain the concept of conservation of energy using equations for an egg drop? Thanks
  A: Well, you're dropping eggs. So first you have the drop from height h. mgh = 1/2 mv^2, where m is ...
Energy11/25/2008
  Q: Why force can't be an energy? Although I know that the force has to multiply the distance so as to ...
  A: What do you mean, why can't it be an energy? That is, in a sense, like asking why sand can't be a ...
electricity11/24/2008
  Q: How much energy could be gained from a 7" diameter circular shape brace (Cu) coil of 300 turnes. The ...
  A: The details aren't quite right, so you should re-pose the question or follow the below link. For ...
galaxy size11/24/2008
  Q: As I understand, the planets revolve around the Sun because of the gravitational pull of the Sun. ...
  A: The range of the gravitational force is infinite, though it gets dramatically weaker with distance ...
Radium watch dial risks?11/23/2008
  Q: While I am not one of those people who worries about every little environmental contaminant, I do ...
  A: Well, having taught radiation safety, I may be able to apply some perspective. It's surprising how ...
bear-bull momentum11/23/2008
  Q: Me and my friends are debating something regarding a bear and a bull. The average 500 kilogram can ...
  A: You'll note that the units are the same for mass*velocity and force*time. There's a reason, ...
quantum11/23/2008
  Q: I was wondering if you could help me out. Why can't you measure both the location and velocity of a ...
  A: If you don't interact with a particle, you can't detect it because you didn't have an interaction to ...
INQUIRY11/22/2008
  Q: I m an engineer , unfortuntly after taking my bachelor degree I found that I unsatisfied with ...
  A: There are jobs in this field, though often applied to theoretical situations involving the real ...
speed of electron11/21/2008
  Q: sir what is the speed of electron in a conductor and what will be it's speed if it is connected to ...
  A: The speed of an electron in a conductor depends on its quantum state, and therefore I'd need more ...
bear-bull momentum11/21/2008
  Q: Me and my friends are debating something regarding a bear and a bull. The average 500 kilogram can ...
  A: I know I've answered this before, but can't find the original question. I'll give you my thoughts, ...
Nuclei Single-particles Harmonic Oscillator Potential11/21/2008
  Q: I am looking into the calculations of a harmonic oscillator potential for nuclei single-particles. ...
  A: First, you're relying on a brief wiki instead of a textbook. Your local library probably has the ...
Help!11/20/2008
  Q: So, in my physics class we just dropped a plastic egg filled with metal washers from the ceiling. It ...
  A: Never seen a lab quite like that, so it would help if you followed up with some more details, but ...
boat hull11/20/2008
  Q: Is there a way to determine if the balsa core sandwiched between 2 layers of fiberglass in a small ...
  A: That would work, probably. Air in the upper parts of the hull would significantly muffle the sound ...
quantum11/20/2008
  Q: I was wondering if you could help me out. Why can't you measure both the location and velocity of a ...
  A: The act of measuring something requires it to interact with another quantum of matter or energy at a ...
electromagnetism11/20/2008
  Q: Estimate the magnetic field that might be obtained close to a thick piece of copper wire which is ...
  A: You'll have to look up the maximum amperage or the starting amperage of the battery for the car ...
boat hull11/20/2008
  Q: Is there a way to determine if the balsa core sandwiched between 2 layers of fiberglass in a small ...
  A: Yes, estimate the volume of the balsa (area estimate times thickness) and do the same for the ...
Query about the electromagnetic forces.11/19/2008
  Q: Sir, I want to know how the interaction between the two poles of a magnet i.e. like and unlike poles ...
  A: Wow, you really asked a difficult question to answer. Unfortunately, the actual answer to this ...
our vision11/19/2008
  Q: When I stand in the roof of a top building, I see a tree or a tower as the end point (i.e., I see ...
  A: I'll take a stab at your question, though it's a little unclear. By "farmost thing" I think you ...
Thermodynamics11/18/2008
  Q: (1)Is the force of the electromagnetic attraction of the molecules of a gas at high pressure ...
  A: 1) Thermal interchange of energy happens during collisions between molecules. They are the source ...
Magnetic reaction time11/18/2008
  Q: What is the speed at which magnetic interactions occur? I realize in some sense this may not be an ...
  A: The magnetic field will become higher due to length contraction nearer to the speed of light. Same ...
Magnetic reaction time11/17/2008
  Q: What is the speed at which magnetic interactions occur? I realize in some sense this may not be an ...
  A: As light is composed of electromagnetic fields, magnetic information is indeed transmitted at the ...
newton's third law of motion11/17/2008
  Q: i am always confused about this law((action====reaction)) Is there any situation in which when the ...
  A: Water provides us with an equal reaction force, but that force is not sufficient to move our large ...
Momentum11/17/2008
  Q: Greetings sir, I am a high school senior and have troubled you in the past.So sorry to bother you ...
  A: No problem on the repeat question. The statement is absolutely correct. Density of metal has ...
Question11/16/2008
  Q: I have a friend who is a chemical engineer, though, he was unable to help me but so far. ...I have ...
  A: The slowdown in the flow of the fluid from injecting the CO2 (whatever your backflow pressure) would ...
Thermodynamics11/16/2008
  Q: (1)Is the force of the electromagnetic attraction of the molecules of a gas at high pressure ...
  A: This is a lot of questions all at once. Yes, it is a function of their position. Not applicable ...
Thermal Infrared Fluorescent Lamps?11/15/2008
  Q: Most fluorescent lamps emit light in visible range. Is it possible to build a fluorescent lamp that ...
  A: It is possible, but it would be expensive and really no more efficient than simply heating a surface ...
RF cooling?!11/15/2008
  Q: Just how can microwaves be used to cool something? Usually they heat things up. ...
  A: The microwaves have momentum, which can be used to cancel out the momentum of motion in tiny ...
newtons laws(pulleys)11/14/2008
  Q: this is a question in my text book,but its kinda like a doubt.the text book says tat if we assume ...
  A: As the 15 kg mass moves down it needs to extend the string on both sides. For every unit distance ...
Work done by a magnet11/14/2008
  Q: I am curious to know if work is done by a magnet in attracting a magnetic material. Since there is a ...
  A: Technically the work isn't done by the magnet itself. Technically the work is done by the response ...
Understanding.11/14/2008
  Q: I subscribed to the Cern Courier and came across this page: The Higgs and LHC. Whilst reading it I ...
  A: Wait, it's not still the woman worried about the LHC causing global destruction, is it? This quote ...
Reductionism Fate11/14/2008
  Q: First off, you seemed the most qualified of everyone here I've looked through, so even if you can't ...
  A: Nuclear fission (where there are many outcomes to the same reaction, as nuclei split unevenly and ...
energy levels11/14/2008
  Q: I am working on a project involving co2 gas under high pressure.It is my understanding that (1)there ...
  A: Phonons are caused by collisions between atoms, the interchange of energy. They are the quantum ...
Helicopter Physics11/13/2008
  Q: I guess I should have been more clear on my last question. I am trying to figure out how fast a RC ...
  A: I'm trying to steer you clear of the Navier-Stokes equation, so try this on for size: ...
Speed of light, time, nuclear fission.11/13/2008
  Q: i have a question concerning the speed of light and special relativity. Let's assume an individual ...
  A: You said the speed of light, so I'll answer for that condition. Nothing happens, because time would ...
condensation11/13/2008
  Q: This may be stupid to you, But I just want to know exactly why and if I can stop it. I built this ...
  A: I have no idea what this box is for, but I'm going to say to remove a tiny piece of the seal at a ...
condensation11/13/2008
  Q: This may be stupid to you, But I just want to know exactly why and if I can stop it. I built this ...
  A: Air tight fit is both a benefit and a problem. On one hand, no moisture can get in, on the other ...
force11/13/2008
  Q: Where do forces come from? And can a body, in and of itself, possess a force as it possesses other ...
  A: Forces are the interactions between objects, not a quantity an object may possess. Where they come ...
physics11/13/2008
  Q: How are gravitational fields and electric fields similar? How are they different?
  A: They both have the same form, where the force depends on a constant of nature, a product of a ...
Cold Energy11/12/2008
  Q: When matter is cold that basically means the particles are slowed down inside of its atoms? Is there ...
  A: Heat is a form of energy. Temperature is directly related to the energy content of material. ...
Reductionism Fate11/12/2008
  Q: First off, you seemed the most qualified of everyone here I've looked through, so even if you can't ...
  A: To the best of our scientific knowledge, the philosophy of Reductionism is absolutely false. The ...
Circles,11/12/2008
  Q: I have had some sleepless nights recently thinking about circles, i (think i) know that a body ...
  A: I will assume you mean with constant velocity to make this easier. This is almost more of a ...
Work done by a magnet11/12/2008
  Q: I am curious to know if work is done by a magnet in attracting a magnetic material. Since there is a ...
  A: Work is done on a magnetic material. The magnetic domains in the material re-align with the ...
Force and contact time11/12/2008
  Q: Nelson, I am a 3rd Degree black belt in Taekwondo and regularly break both wood and concrete. I ...
  A: Breaking stuff with your hands and feet is a little out of my experience range, but I'll take this ...
energy levels11/10/2008
  Q: I am working on a project involving co2 gas under high pressure.It is my understanding that (1)there ...
  A: Temperature is technically the result of the number of available quantum states of the molecules. ...
Drag11/10/2008
  Q: Steve, if you are driving a car down the road at 65 MPH, how much wind force is pushed onto the road ...
  A: Wind speed being pushed down on the road...that quantity doesn't make sense unfortunately. You can ...
Pseudo Geiger Mueller detector11/8/2008
  Q: Ran into what I thought was a really neat demo which showed the basic concept of radiation detection ...
  A: First, thanks for showing me this site, it's fantastic. I'm always looking for neat do-it-yourself ...
Why?11/8/2008
  Q: can you please explain why water sprays off a rapidly turning bicycle wheel? Thanks!
  A: Inertia. The water, moving with the wheel, has momentum and inertia. The forces that cause the ...
Center of Mass11/8/2008
  Q: A uniform circular plate of radius 2R has a circular hole of radius R cut out of it. The center C' ...
  A: Well, for one thing the units don't even match up. You're trying to subtract kg*m from kg^2 ...
0 Mass11/7/2008
  Q: Dr. Nelson: Would you please explain the menaing of a particle with 0 mass? If something has 0 ...
  A: A photon is a quantum, or particle, in that you can only absorb or emit one as a whole unit. You ...
energy levels11/7/2008
  Q: I am working on a project involving co2 gas under high pressure.It is my understanding that ...
  A: The kinetic energy of gas molecules depends only on their temperature. Pressure depends on both ...
Magnet11/6/2008
  Q: I just wanted to know if there is a super magnet (no bigger than your fist) that can move a car when ...
  A: They make magnets with a few hundred pounds of lifting strength, but remember Newton's Laws...it's ...
Double slit experiment11/6/2008
  Q: In the double slit experiment, why does an interference pattern show up behind the slits when ...
  A: There's a great youtube video for this which explains it all, but requires some further explanation: ...
Magnet11/6/2008
  Q: I just wanted to know if there is a super magnet (no bigger than your fist) that can move a car when ...
  A: Depends on the car, the strength of the magnet (I know some that could have a pull of hundreds of ...
reg waves in sea11/5/2008
  Q: What causes waves in the sea?. Why some seas have no or very less waves? Regards. Moosa
  A: This is very complex indeed. Motion of water is converted into waves, this motion can come from ...
Current at all points?11/5/2008
  Q: My question concerns the fact that in a simple series circuit, the current is the same at all points ...
  A: Of course there's a time lag, nothing can travel faster than the speed of light. The electric field ...
Current at all points?11/5/2008
  Q: My question concerns the fact that in a simple series circuit, the current is the same at all points ...
  A: Yes, there's a very very slight difference in charge distributions around a circuit that keeps ...
Physical characteristics of liquids splashing11/4/2008
  Q: I am not putting you on. I seriously am curious about this. Not that I am a hypocondriac about ...
  A: The amount of splashback will be far less important than the content. The liquid with downward ...
geosynchronous orbit??11/4/2008
  Q: A satelite in a geosynchronous orbit has a period of revolution of: a) 5400 s b) 3600 s c) 43200 s ...
  A: I don't answer homework questions directly, so I can't just point you at a formula. Geosynchronous ...
bernouli's theroem11/4/2008
  Q: When an object is moving, it has two kinds of energies.. Kinetic energy(by virtue of its movement) ...
  A: These are a lot of questions. First, this is not a new type of energy, pressure is energy density ...
Acceleration10/31/2008
  Q: In the car, what can produce acceleration? Thanks in advance!
  A: Applied forces produce acceleration. When the engine applies torque to the wheels, the wheels apply ...
x-ray machine10/31/2008
  Q: I'm not sure if i'm in the correct area, but i thought i'd give it a shot anyways. So here it goes: ...
  A: Tantalum, with the drawback that it's hard to machine. Tantalum has all the properties you mention ...
Mass10/29/2008
  Q: So what causes something to have its mass?
  A: The current theory (unproven) is that this is caused by something called the Higgs boson. This has ...
Gravity10/28/2008
  Q: What is gravity? Why don't we know what gravity is? ANSWER: We do know what gravity is, although ...
  A: No, in my first sentence I told you what gravitation is. It *is* the distortion of spacetime. Then ...
Room Temperature10/28/2008
  Q: If you have a cold room (say 10 degC) and you want to heat the room to say 20 degC so you get a ...
  A: Yep, this one's easy for me to answer because you were smart enough to answer it for yourself with ...
Gravity10/28/2008
  Q: What is gravity? Why don't we know what gravity is? ANSWER: We do know what gravity is, although ...
  A: Gravitation is the stretching or curving of spacetime. If you put your pencil on the Earth, you put ...
Now its Newton10/27/2008
  Q: I hope I don't sound like a botheration to you but I'm preparing for my final exams at senior high ...
  A: Your first of your two equations is correct, the sum of forces = mass*acceleration. Technically ...
Physics10/27/2008
  Q: I just need a better understanding on how right-angled prisms work dealing with reflection. Thank ...
  A: Right-angle prisms generally rely on total internal reflection. ...
Blocking the Sun for Climate Control10/27/2008
  Q: Steve, this may sound stupid to you but if one were to place on top of a blimp a "sun shade/sun ...
  A: Complex question, but the sun has an angle due to its size of 0.5 degrees, so if you fly it high ...
Gravity10/26/2008
  Q: What is gravity? Why don't we know what gravity is?
  A: We do know what gravity is, although we've never directly observed a gravitational wave. General ...
electronics10/25/2008
  Q: Sir! why do different colours appear instead of real ones on a TV screen when a magnet is brought ...
  A: Magnets deflect moving charged particles. TV phosphors are illuminated by a beam of electrons, ...
Audio/Video recordings10/25/2008
  Q: I wonder how information are stored in audio tapes and video tape/CDs?. If magnets store these ...
  A: There are areas of ferromagnetic material on these tapes. Atoms in ferromagnetic material have ...
magnetic permability10/25/2008
  Q: I am stuck with a concept in physics. I am using the magnetic permabililty of air in an equation but ...
  A: Currents traveling in the same direction will attract one another, so I assume you meant attractive ...
quanta of the electromagnetic force10/24/2008
  Q: Can you explain what is meant by the universe's Total mass deficit ? What is anti matter ? Can a ...
  A: Mass deficit usually refers to galactic mass deficit. We don't observe enough matter in galaxies to ...
Twilight detector10/22/2008
  Q: i would like to construct a simple twilight detector lamp for my electrical engineering class. I ...
  A: These devices basically consist of a photodiode or solar cell and a voltage detector. ...
antifreeze10/22/2008
  Q: Steve... If the antfreeze in my car reads -20 degrees C when tested, what will happen if the ...
  A: We used to keep dry ice (-78C) in antifreeze all the time and it would just be a little thick. But ...
sequential inflation of a garden hose10/21/2008
  Q: I have taken physics in undergrad. How can i vary the length and width of a rubber or plastic tube ...
  A: Not really, you want a pressure that you set as the maximum before the valves open. It's kinda like ...
drift velocity ¤t electricity10/18/2008
  Q: why is the direction of current & drift velocity same if particle is positive ,& direction of ...
  A: Current is defined as going from positive potential to negative potential. The drift velocity is ...
friction10/16/2008
  Q: My question is that (1)by experience we know that wide tyres offer better traction to a vehicle, ...
  A: That appears to be one of the three major functions of tread, to cut through dirt and other ...
General Relativity10/16/2008
  Q: I read that according to General Relativity Theory, gravitation is not a force but something else. ...
  A: A force is that which causes a body with mass to accelerate. Therefore gravitation is a force. ...
Cause of gravitational force10/16/2008
  Q: What is the cause of gravitational force between two bodies? What makes two bodies to attract each ...
  A: ***As a warning, you're asking questions to which there are no quick and simple answers. There's no ...
Clouds10/15/2008
  Q: Small clouds in the sky seems to move in the sky and unite. What makes the clouds to move and unite ...
  A: They usually don't join, they usually just drift along, but occasionally they do. Appearances can ...
Theories10/15/2008
  Q: What exactly qualifies a theory (such as general relativity, or any other physical theory) and how ...
  A: Interesting question. Anyone can have a theory. An *accepted* theory is one that's presented ...
gravitational force10/15/2008
  Q: This may be a stupid question but here it is. Would it be possible to build something so massive ...
  A: It doesn't have to be large at all, we measure this all the time. It's a classic experiment called ...
friction10/14/2008
  Q: My question is that (1)by experience we know that wide tyres offer better traction to a vehicle, ...
  A: They're not incompatible, the force of friction being area-independent is somewhat dependent on the ...
physics10/8/2008
  Q: Can water be compressed to a solid? As in: A theoretical planet composed entirely of water, about ...
  A: See here for the many anomalous properties of water: http://www.lsbu.ac.uk/water/anmlies.html ...
Hazards of 400 nm lasers?10/8/2008
  Q: What hazards -- other than thermal burns -- does a 400-nanometer-wavelength continuous [i.e. ...
  A: Mostly the hazards you saw on the wiki page you attached to the question. The human eye can see ...
Spinning Tops10/8/2008
  Q: How can I explain the physics principles involved in spinning tops to 5th grade students? It is a ...
  A: There's a good demonstration you can do if you can find a chair or stool that rotates and a bicycle ...
About generation of current from rotional motion10/8/2008
  Q: Nelson. I am a molecular biology major with interest in, but little understanding of, various ...
  A: The tube must have been connected to a generating mechanism more than just a diode. A diode doesn't ...
Electric Field and Application10/7/2008
  Q: What is the importance/relevance to know the electric field distribution of a electrical apparatus? ...
  A: Electric field intensity is important to know for a couple of reasons I can think of off the top of ...
Conservation of Energy10/6/2008
  Q: According to the law of conservation of energy, the energy is always preserved. Suppose if eletrical ...
  A: If the energy is absorbed in the atmosphere it is turned (by the molecules in the atmosphere) into ...
Cycling backwards10/5/2008
  Q: Sir ill be highly obliged if you could answer this question my sister put to me the other day... Q. ...
  A: On some stunt bikes it is actually possible to pedal backwards, but on most bikes you can't. Listen ...
calorimetry10/5/2008
  Q: 1) if we take a solid which contracts on being melted(like, for example ice which contracts due to ...
  A: Water exhibits anomalous behavior. Since I'm a nuclear physicist, I consulted with friends in ...
Going for Grey9/28/2008
  Q: Am I correct in thinking that if traveling at close to the speed on light, the frequency that light ...
  A: Yes, that's the doppler shift. An object which was grey would have all its light shifted towards ...
Calculate properties of matter9/28/2008
  Q: I want to calculate the mass properties or density of the matter of interest //Mohan ANSWER: No, ...
  A: We can't simply calculate mass, mass is a measured quantity. It's observed in the laboratory, not ...
Calculate properties of matter9/27/2008
  Q: I want to calculate the mass properties or density of the matter of interest //Mohan
  A: No, using only the speed of light it is not possible to calculate such properties. You need many ...
Going for Grey9/26/2008
  Q: Is there an opposite colour to grey? In the same way that red and green are opposite.
  A: Sort answer: no. Slightly longer discussion. Red and Green are not physically "opposite." This ...
Law of gravitation9/26/2008
  Q: I read that according to Law of Gravitation all bodies in the universe attract each other. Does it ...
  A: Of course the Earth is far larger than the mountains that sit on it. So the mountains may attract ...
LHC9/25/2008
  Q: So do you think i'm worrying over nothing. The whole thing has mad me very ill and I just wanted ...
  A: I'm not remotely qualified to give you medical advice. Personally I would chalk this up to an ...
coulomb charge and electrolysis9/25/2008
  Q: my question is i have a 2C charge, how to i make it a positive anode and negative cathode with this ...
  A: You make a positive anode and negative cathode by putting 2 C of charge on the positive anode and -2 ...
Friction9/24/2008
  Q: When a block rests on a truck that is moving with uniform velocity, the block also moves with the ...
  A: The force of friction is zero in this case, as there is no acceleration. So you don't need to go ...
speed of light9/22/2008
  Q: If you were moving half the speed of light and you shined a light infront of yourself, would that ...
  A: No, light always travels the same speed. It's one of the more difficult notions of relativity, I ...
speed of light9/22/2008
  Q: If you were moving half the speed of light and you shined a light infront of yourself, would that ...
  A: Moving at half the speed of light relative to what? Presumably, you mean an observer watching the ...
gravitation9/21/2008
  Q: why is the gravitational potential enrergy of a body on mass m the surface of earth in the ...
  A: It's not U=-GMm/r^2, it's U=-GMm/r. You were thinking of the equation for force and not energy. ...
electrical9/20/2008
  Q: can 11kv of electricity would be converted into light to pass through fiber optics ANSWER: Short ...
  A: Nothing can pass light through the fiber with 100% efficiency, especially over that extreme ...
LHC9/20/2008
  Q: I have read on the CERN website that stable black holes if produced could settle into the core of ...
  A: Oh, yes. You keep saying that you've gotten information from the CERN website. You should go here: ...
LHC9/20/2008
  Q: Which can be absorbed by the earth. If this were to happen then how long would it take to destroy ...
  A: I'm trying to not be offended that you ignored my explanation of how this is impossible and ...
fiber optic cable9/19/2008
  Q: If fiber optic cable is made out of very thin strands of glass, how can it be flexible? It seems ...
  A: Nope, kinda like a copper plate is quite hard but thin copper wire is quite flexible. It's a matter ...
Vectors/Termianl velocity experiment9/19/2008
  Q: For a project at school I was going to measure the terminal velocity of objects in air by using a ...
  A: The problem here is that you have to measure the speed of the air at the height of the object. If ...
LHC9/19/2008
  Q: Which can be absorbed by the earth. If this were to happen then how long would it take to destroy ...
  A: Protons with even higher energy than the LHC can produce would be far more likely to produce black ...
proving an arguement with a friend9/19/2008
  Q: So my friend and I were arguing over how sniping can all calculated with calculus, including factors ...
  A: Anyone who turns a character in a video game knows that video games are digital and only have finite ...
electrical9/18/2008
  Q: can 11kv of electricity would be converted into light to pass through fiber optics
  A: Short answer: yes. Longer answer: Not with 100% efficiency, no, you need something like a laser ...
Water Boiling9/17/2008
  Q: She says that something is released in the bubbles formed when you boil water. If this is so can ...
  A: Well obviously something fills the bubbles or they'd collapse. That's air for the little bubbles ...
Physics9/17/2008
  Q: what is used to calculate the speed of sound
  A: Either the dispersion relation for the fluid that the sound travels in, or a direct measurement are ...
momentum9/17/2008
  Q: Which should be the best on knocking the bear down- a lead bullet or a rubber bullet with the same ...
  A: This question is a little vague. What bear? Is it moving, standing, etc? Does the fact that a ...
radioactive decay9/16/2008
  Q: my question arises from the fact that it seems not to exist information at atom-level that makes one ...
  A: Interesting question, I've wondered about something that sounds along these lines when I've talked ...
quantum computers9/16/2008
  Q: Is a quantum chemical computer possible? Could you explain further? ANSWER: Yes. No. Well, a ...
  A: Ahhh, we're mixing chemical computers with quantum computers. Quantum computers generally are ...
radioactive decay9/16/2008
  Q: my question arises from the fact that it seems not to exist information at atom-level that makes one ...
  A: I'm not sure what a decay ratio is, but I'll assume you mean either a half-life or a fraction of ...
quantum computers9/16/2008
  Q: Is a quantum chemical computer possible? Could you explain further?
  A: Yes. No. Well, a quantum computer is possible. What you mean by a quantum chemical computer is ...
Time9/15/2008
  Q: Steve, I think it's generally accepted that time changes due to velocity and gravity. Beyond ...
  A: The speed of light being constant is well-measured, not assumed. The theory of relativity depends ...
Time9/14/2008
  Q: Steve, I think it's generally accepted that time changes due to velocity and gravity. Beyond ...
  A: We have many experimental proofs, from particles whose half-life is altered (high energy cosmic ...
need help with ohm's law9/14/2008
  Q: i am having a problem in making authentic questions about ohm's law please give me some authentic ...
  A: You can ask about the resistance of a wire of length L, area A, and resistivity rho. You can sketch ...
LHC9/14/2008
  Q: I have been very worried about this experiment and have become very ill. I have read the conflicting ...
  A: If there was any danger, we'd all have been destroyed naturally billions of years ago. It really is ...
making mass from energy9/12/2008
  Q: In nuclear physics we often hear about energy coming from mass e.g.Nuclear bombs and nuclear power. ...
  A: That's impossible, becuase you'd have to make the components of anti-hydrogen, which then annihilate ...
making mass from energy9/11/2008
  Q: In nuclear physics we often hear about energy coming from mass e.g.Nuclear bombs and nuclear power. ...
  A: Of course, high-energy photons are naturally converted to matter-antimatter pairs all around you, ...
Small EMP9/11/2008
  Q: I've been told that one of the few causes of an EMP is a large explosion. Is there anyway to create ...
  A: There's nothing minor you can set up next to a building. It has to have too much energy to cause ...
Small EMP9/11/2008
  Q: I've been told that one of the few causes of an EMP is a large explosion. Is there anyway to create ...
  A: Yes, but no explosion. A single pulse from a Tesla coil will do the trick. However, the energy ...
CLouds9/10/2008
  Q: I asked this question of a meteorologist, but he kept saying that the answer lay in surface ...
  A: He probably interpreted your question as meaning how a single droplet wouldn't blow up. Not the ...
Protons9/10/2008
  Q: Steve Where do scientists get the protons from to use in experiments? Simon
  A: That's shockingly easy in terms of many things scientists do, though I understand how "proton beams" ...
Earth's inner liquid dynamo9/10/2008
  Q: this is a follow up in a way. I thought the Dynamo was producing the Earth's magnetic field. Is it ...
  A: You might want to consider asking a geophysicist about the relationship between the dynamo and ...
Science9/10/2008
  Q: how centripetal force is involved in the operation of a washing machine? How the spin dryer of the ...
  A: In order to keep the clothes spinning in a circle, the barrel of the dryer presses against them to ...
earth's mantle9/9/2008
  Q: Perhaps this isn't exactly your field but I can't get an answer anywhere? I understand that the ...
  A: You don't have to add energy for that, the momentum of the Earth's inner liquid dynamo is enormous ...
electricity9/9/2008
  Q: sir what is terminal velocity and drift velocity and is there any way to construct two wires of same ...
  A: Terminal velocity is generally used to refer to the velocity a falling body achieves where its air ...
Charging an inductor9/9/2008
  Q: I am experimenting with voltage gains based on LC ratios and low coupling between a primary and ...
  A: The rate of change of the current may be slower, but the total magnetic flux (field times area) may ...
LHC9/8/2008
  Q: im pretty sure you know what the LHC or CERN im worried because in 2 days they will start it up and ...
  A: Yes, it's telling you that your mind correctly identified black holes and strange matter eating the ...
earth's mantle9/8/2008
  Q: Perhaps this isn't exactly your field but I can't get an answer anywhere? I understand that the ...
  A: The magnitude of the Earth's size is perhaps what makes the analogy not quite work. A pan of milk ...
Charging an inductor9/8/2008
  Q: I am experimenting with voltage gains based on LC ratios and low coupling between a primary and ...
  A: The voltage depends greatly on the rate of change of the peak magnetic field in the secondary coil. ...
earth's mantle9/8/2008
  Q: Perhaps this isn't exactly your field but I can't get an answer anywhere? I understand that the ...
  A: Nuclear decay is the primary thing *adding* heat to the mantle, but mostly it's just really hot and ...
about drinking bird9/7/2008
  Q: Have you heard about drinking bird?? Do you think the drinking bird performs work? ANSWER: I've ...
  A: No, the bird does indeed work (as in it functions as designed). Gravity is the force that acts on ...
Twins paradox9/6/2008
  Q: As I understand it (or I suppose I should say "if"), it is deemed a paradox not because the twins ...
  A: Here's a way to think about it that most explanations don't usually cover. Every inertial reference ...
microwaved water9/6/2008
  Q: I have noticed that when heating water to the boiling point in a microwave in a ceramic cup, the hot ...
  A: The water is superheated, meaning above its boiling point. The problem is that there are no places ...
i need ur help9/4/2008
  Q: i have been admitted to a institution to read physics and solar energy and i dont know anything ...
  A: If would help if I knew something about the institution and if you can be more specific about what ...
another bet9/2/2008
  Q: in theory: I was once told that if you have a rifle in a vice at a specific height and also had a ...
  A: In a classical approximation this statement is true. This is in a vacuum, and neglecting the ...
egg drop container9/2/2008
  Q: I need a good egg drop container for school all my ideas fail!!!!!!!!!!Must not use these items- ~ ...
  A: My first thought is to use a bag of Jell-O. Simple, effective. Gel up the egg inside the gelatin. ...
electricity and power9/2/2008
  Q: I have a 55 watt power source and need to power a machine. Is there a way to increase the power ...
  A: There are many remote controls (look at your basic RC car with a manually-operated remote control) ...
electricity and power9/2/2008
  Q: I have a 55 watt power source and need to power a machine. Is there a way to increase the power ...
  A: Not with a standard computer. Most standard computer cases require at least 230 Watts of power at ...
"Gravitational Constant"9/1/2008
  Q: Sorry to bother you with what is probably a dumb question. But, if gravitational attraction between ...
  A: The gravitational force is *approximately* constant in our human experience, because the distances ...
air compression9/1/2008
  Q: I have a steel tank 70 cubic feet in volume. I have an air compressor, output 900 CFM @ 350 psi. ...
  A: Seems simple enough. The product of the absolute pressure (gauge pressure minus atmospheric ...
Dust on my TV screen8/31/2008
  Q: As of late, dust has been forming on my TV screen in an odd manner. It forms in the exact center, ...
  A: The same thing happens to my TV! There must be more static electricity building up in that region. ...
lorentz transformation?8/31/2008
  Q: what is lorentz transformation? and what do the symbols mean? and i have found 2 different equations ...
  A: Well, technically the second one refers to a time interval and not an absolute time. But it's ...
electricity and magnetism8/30/2008
  Q: . 1) sir convential current says it flows from positive to negative charge sir what is the positive ...
  A: Positive charges in matter are protons. Atoms are neutral, because they contain equal numbers of ...
Response to a past question8/27/2008
  Q: i tried to send a follow up, but it wouldnt work. my past question was about relativistic mass. and ...
  A: You can measure it. Say you know its charge and you accelerate it across a voltage (to give it a ...
gravitation8/25/2008
  Q: few questions 1) why the earth's orbit is like an ellipse why it's not a circle? 2) if the pull of ...
  A: It would increase in radius, which would sap some of the potential energy and slow it back down at ...
gravitation8/25/2008
  Q: few questions 1) why the earth's orbit is like an ellipse why it's not a circle? 2) if the pull of ...
  A: I'll try to answer them in order: 1) This is one of Kepler's observational laws. The orbit would ...
Atmospheric explosive phenomenon8/24/2008
  Q: I hope you are able to answer this question. I have been looking online for an answer now for a ...
  A: Atmospheric phenomena are weird and hard to explain a lot of the time. It was during a lightning ...
Einstein's equation8/23/2008
  Q: Is theory of conversion of mass into energy correct? I mean how can anything can travel faster than ...
  A: Mass and energy are converted from one form to another all the time in natural processes like pair ...
nuclear8/22/2008
  Q: I think peak oil is here and it looks like nuclear fission is our nearest straw. I've heard uranium ...
  A: Yes it could, but there are three ways to solve this. First, there are probably undiscovered ...
rain8/22/2008
  Q: I have for years wondered why a rainfall shower is of greater intensity just before the end of the ...
  A: Actually, I'm not sure about this since it's a little outside my expertise, so you should ask a ...
Electric motor current draw8/21/2008
  Q: I have a question about 12v DC motor current draw. I have read in several books on electric motor ...
  A: No, the current flowing through the motor will determine the amount of work it does. Because power ...
physics8/21/2008
  Q: My friend and I would like to ask you few questions about physics. please help us. Thanks 1. Is it ...
  A: 1) Yes, but it's inefficient. Plenty of farmers have fermented their own corn into ethanol for ...
quz8/21/2008
  Q: How we can study the move of the car which is moving on the straight and horizental road ?
  A: Time it as it passes lines or markers on the road. Use photogates. Radar and laser Doppler shift. ...
relativistic mass of light8/20/2008
  Q: from what i kno, energy something has, the more mass it has since they are inter related, right? and ...
  A: Watts per second is the wrong unit. Include units in your equations and you won't make mistakes ...
gravitation8/20/2008
  Q: sir i want to ask that if earth starts revolving faster around sun so will it's orbit increase or ...
  A: Most would say it would increase, but that's slightly inaccurate. If the Earth's orbit increases in ...
motions8/18/2008
  Q: ANSWER: Neglecting air resistance, yes. Including, of course not. Including it, it will lose ...
  A: Equations aren't really necessary, just terms. Kinetic energy is given by 1/2 mv^2, potential ...
motions8/18/2008
  Q: hi sir i want to ask that if i fire a bullet vertically upward will it hit the ground with same ...
  A: Neglecting air resistance, yes. Including, of course not. Including it, it will lose energy ...
physics8/17/2008
  Q: what are the possible things that would happen if air was an electric conductor?
  A: We wouldn't use much electrical power, for one, since we wouldn't be able to create voltage between ...
Random physics questions.8/16/2008
  Q: How the hell does anti-matter fit in? How does it form? How does it react with matter (I have vague ...
  A: It's not lost from existence, it goes toward the singularity in the center. At that point the laws ...
physics8/16/2008
  Q: A common misconception about heat energy is that 'heat rises'. Many examples are given; it's ...
  A: Yes, a misunderstanding. Less dense substances rise, more dense substances fall. Substances at ...
Random physics questions.8/15/2008
  Q: How the hell does anti-matter fit in? How does it form? How does it react with matter (I have vague ...
  A: You're asking things that are a mix of two types of questions: 1) I can't answer without giving ...
Random physics questions.8/15/2008
  Q: How the hell does anti-matter fit in? How does it form? How does it react with matter (I have vague ...
  A: The first one is kinda vague, so I'm going to assume you meant to ask what anti-matter is. First I ...
conversion of chemical to radiative heat8/6/2008
  Q: What determines the rate at which chemical heat (convection) becomes electromagnetic heat ...
  A: Emission of radiation from a hot body is governed by the Stefan-Boltzmann Law: ...
water flow8/6/2008
  Q: So i want to know if water flow into a container can be great enough to prevent the air in that ...
  A: Flow is caused by differences in pressure. Therefore, if water pressure is lower than the air ...
Light speeds and relative single point objects.8/2/2008
  Q: What happens if you spin a single object, in a place relative to the things around it, at the speed ...
  A: I assume you mean an object's edge. It can't be done. You can get close, but particles can't be ...
Rockets7/30/2008
  Q: I am a university level student and this is the question on which I have to research but don't know ...
  A: Research? I can definitely start you out, though obviously the explanation has to be yours (your ...
Light and Sound7/30/2008
  Q: I often come up with weird "if.. would" scenarios pertaining to physics, and I wanted to know if you ...
  A: Lit is a matter of perspective. To perceive "lit" your eye would have to absorb light. Eventually ...
behavior of gravity7/29/2008
  Q: I'd like to try and get a better intuitive sense of gravity by learning the answer to thisSuppose I ...
  A: Assuming that the orbit didn't take it too close to either the Earth or Moon to throw off the ...
Do human share the same colour system?7/29/2008
  Q: I want ask why do human seem seem to be able to agree on following phenomenon? -Is it true that ...
  A: Human eyes share many physical characteristics and respond in very similar ways to colors. There ...
wind force7/29/2008
  Q: I have a question about the force of wind. Is there an equation that factors in air pressure in ...
  A: The 0.00256 is simply a constant related to the density of air. It relates to the energy dissipated ...
space flight7/29/2008
  Q: #1 is the Van Allen belt real? and what, if real, what is its role in space flight? We as humans ...
  A: Yes it is real. Charged particles get trapped in magnetic fields, and cosmic rays in the Earth's ...
toothpick egg drop project7/28/2008
  Q: Where can I get information (at an eighth grade level) for designing an egg drop container out of ...
  A: There aren't really many hard and fast physics rules for making an egg-drop container, more ...
wind force7/28/2008
  Q: I have a question about the force of wind. Is there an equation that factors in air pressure in ...
  A: The short answer is yes, there are equations that will give you that. The long answer is that it ...
newtons 3rd law7/24/2008
  Q: Why when you would hit a soft object will newtons 3rd law not apply and an equal and opposite force ...
  A: It is applying the same force. The third law is not violated. The reason it accelerates forward ...
air as an insulator7/24/2008
  Q: why is air such a good insulator?
  A: Short answer: density. Air has about a thousand times less molecules/volume to conduct heat. ...
Broken window7/24/2008
  Q: How can I tell if a window was broken on the inside or the outside. Most of the glass is on the ...
  A: I think the logical conclusion is that you're correct. A blunt or sharp object breaking the window ...
water wicks7/24/2008
  Q: I have been trying to find a wick that will be able to wick water upwards as far as possible. Q1) ...
  A: What I was able to find was more about speeds for ground water sampling and not absolute attainable ...
Broken window7/24/2008
  Q: How can I tell if a window was broken on the inside or the outside. Most of the glass is on the ...
  A: Please send more information in a follow-up question (there should be a link to ask one on this ...
water wicks7/23/2008
  Q: I have been trying to find a wick that will be able to wick water upwards as far as possible. Q1) ...
  A: The short answer to Q1 is yes, of course gravity eventually causes stars to collapse and will limit ...
electricity, solar cells7/23/2008
  Q: if solar cells can convert photons to electricity, why not tune the 'solar' cells to convert gamma ...
  A: Such devices have existed for decades to convert beta and alpha radiation into light (via a ...
electric heater efficiency7/23/2008
  Q: How can there be any significant difference in performance among 1500 watt electric heaters?
  A: The basic physics may seem to say no and it's pretty closely correct. But there may be differences ...
Pressure7/21/2008
  Q: If I took a bath towell, placed it in a body of water so the towell is entirely saturated with the ...
  A: To follow up on this, since I just got my first hostile response question for refusing to answer ...
Physical States7/19/2008
  Q: When water is frozen it takes up more space than liquid water, and when it is hot it evaporates and ...
  A: No water only takes up more space because it forms hydrogen bridges and makes a crystal structure ...
X-Ray7/19/2008
  Q: I'm just trying to settle a questions my friends were discussing about x-rays. With electrical ...
  A: No, lead can different different types of metal but it's not the only one. And it doesn't make a ...
Refraction7/19/2008
  Q: Sir, I am a 10th class student, my question is, I want to know how does the Refractive Index affect ...
  A: http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/refr.html#c1 You can see that if you raise the ...
colour spectrum7/18/2008
  Q: Violet and Indigo are at the top of the colour spectrum. But where do Pink, Purple and Mauve fit in ...
  A: Pink light isn't a single color, it's a mix of red and white light. White light is a mix of all the ...
Atom7/17/2008
  Q: What causes the electrons to orbit around the nucleus?
  A: Electrons have a negative charge. Protons in the nucleus have a positive charge, attracting them to ...
gas mixing7/16/2008
  Q: Assume that you have two sealed chambers. each contains different gas (example - Oxygen in one and ...
  A: The specifics of "time scale" for this question are a little vague, and so are the dimensions of the ...
proper readings from a multimeter/tester7/10/2008
  Q: Nelson, I am developing a novel fuel cell/battery (iron-air) and my only stumbling block is how to ...
  A: It appears (hard to say without seeing the design) that your design involves problems with the cell ...
physics7/8/2008
  Q: Is there a working defintion of what cold is? Heat is a wave, what is 'cold' and how is heat removed ...
  A: You can preview a whole book on cryogenic engineering on google books here: ...
chanign heat back into mechanical energy7/5/2008
  Q: I was wondering what kind of systems and methods can be used to turn heat back into mechanical ...
  A: The car's engine is an example of something using heat (from burning fuel) to create mechanical ...
...Nucleus...7/1/2008
  Q: ..i am B.tech student..i have some doubts regarding nuclear physics.. 1)whether antiproton is ...
  A: That's a lot of questions. Let me go by the numbers. 1) The antiproton is stable as far as we ...
buzz in room of house6/28/2008
  Q: Dr. Nelson - Over the last week there has developed a high-pitched buzzing noise in an upstairs ...
  A: Well, one last thing. The device probably has a chopping power supply or some kind of internal ...
buzz in room of house6/25/2008
  Q: Dr. Nelson - Over the last week there has developed a high-pitched buzzing noise in an upstairs ...
  A: I'd try something first, like plugging in an iron (draws a good bit of current) or other silent ...
NEW OPTICAL PHENOMENON6/24/2008
  Q: sir can you tell me what optical phenomenon is acting here - ...
  A: My first guess is that you've got polarized lenses and a polarized camera or some kind (or a camera ...
kinetic coefficient6/24/2008
  Q: .. could you please explain to me in simple terms how I would find the average kinetic coefficient ...
  A: The physics here is all out of whack. I don't know why you're dividing force by distance (that's ...
should we spend time in the sun figures ?6/23/2008
  Q: how can i get data that i can process to calculate percent graphs? plot a graph and interpret trends ...
  A: A quick google search of "sunscreen cancer trends" revealed that there's a government website with ...
electric motors and magnets6/22/2008
  Q: In a simple electric motor with field magnets and a split-commutator, can you tell me what ...
  A: Check out page 59 and 60 of this powerpoint for a graphical representation of a split commutator. ...
Magnetism6/21/2008
  Q: I understand that heat causes demagnetisation. Why then do my drill bits become magnetised when ...
  A: The demagnetization of metal at high temperature happens above the curie temperature. However, upon ...
thermodynamics6/18/2008
  Q: I'm so confused. I have worked out the answer to the following problem and I was told that my ...
  A: As far as your solution being one way to work it out, that's OK. But I've discovered an error in ...
thermodynamics6/18/2008
  Q: I'm so confused. I have worked out the answer to the following problem and I was told that my ...
  A: You've got some really wrong units here, force is not in Joules (for example). Just consider ...
motors & magnets6/17/2008
  Q: Does this answer the problem of high-voltage power lines making a buzzing sound, using the motor ...
  A: That is approximately why they hum at 60 Hz, but buzzing is different. Actual buzzing sounds from ...
relativity6/17/2008
  Q: 1)According to relativity,noting can travel faster than light.So if we have a bullet that is ...
  A: Interesting questions. Relativity isn't my research area, but I do get a lot of questions about it ...
electrons6/16/2008
  Q: Here is myDescribe what happens to electrons when one material is charged negatively by rubbing it ...
  A: The part about the conductor at the end is a little superfluous, but OK. The real difference in the ...
factors affecting friction6/16/2008
  Q: I need to conduct an experiment. I am not looking for you to do my work for me. I will be doing ...
  A: First, the theory of friction is described quite well in hyperphysics for some background reading: ...
GCSE question should we spend time in the sun?6/16/2008
  Q: thank you
  A: This is a little outside my expertise, as I'm a nuclear physicist and not a medical doctor. One of ...
nuclear physics6/15/2008
  Q: What are the approximate velocities of alpha, beta, gamma and x- rays?
  A: Gamma rays are a form of light, so they travel at the speed of light. Alphas and betas have mass, ...
physics6/11/2008
  Q: what are the different branches of a physics
  A: This is a matter of some debate, and your question is slightly unclear. There are four major areas ...
Magnet ONLY pushes in ONE direction6/10/2008
  Q: http://www.youtube.com/watch?v=xb8wwkdtz0M Can you explain this ?
  A: My take on it is (hard to see from a youtube video) that from the cone shape he's created a magnet ...