Physics/Questions Answered by Expert Richard J. Raridon
| Subject | Date Asked |
| Mass energy | 1/28/2012 |
| Q: Where does the idea come from that energy is "within" mass, when Einstein's equation plainly ... A: Einstein's equation does not say E = (1/2)mv^2 (kinetic energyc. That dates back to Newton. ... | |
| Phsyics Exam | 1/22/2012 |
| Q: I have an assignment that I was absent for and it's on "Waves and Vibrations." I have no idea what ... A: 1. Period T = 1/f 2. It depends upon the medium 3. A. 1.8m, B. 0.675m/s C. 0.375/s D. 2.67s 5. A. ... | |
| free fall impact | 1/19/2012 |
| Q: How to calculate impact of a load free falling from certain height? e.g. what would be the impact ... A: You can calculate the momentum of the load as it hits which is mv = (7256kg)(4.427m/s) = 32124 ... | |
| Mechanical Advantage of a specific pulley system | 1/13/2012 |
| Q: I have a question regarding the mechanical advantage of a specific type of pulley system and was ... A: You are correct. I hadn't thought about pulleys for awhile. The theoretical mechanical advantage ... | |
| Physics Vector Addition | 1/12/2012 |
| Q: A sailboat is heading 35o East of North at 7.2 knots. The ocean current is 25o South of East at 1.2 ... A: East components = 7.2sin35 +1.2cos25 = 5.218 North components = 7.2cos35 -1.2sin25 = 5.393 Resultant ... | |
| motion on curved wall | 12/20/2011 |
| Q: Sir I am confused that why in death well(a person motorcycling on slightly curved vertical walls)the ... A: There's friction between the tires and the walls that allow him to go forward. There's also ... | |
| Physics:Fluids and work | 12/17/2011 |
| Q: why are pressure and work scalar quantity even when pressure has direction or in its formula, force ... A: To understand why pressure is a scalar, go to en.wikipedia.org/wiki/Pressure and scroll down to ... | |
| Fluid pressure | 12/15/2011 |
| Q: I've read about a formula that calculates fluid pressure, p=wh. Where w-weight density/unit volume ... A: Sure, the total force (weight) does depend on both height and volume but pressure is force per unit ... | |
| Physics | 12/12/2011 |
| Q: A projectile is launched from a top of a mountain on a distant planet at an angle of 35.8 degrees ... A: the volume of the prism is 11.2(2.54)(230)(19.6) = 128243.584cm^3 which has a mass of 101312.43g. ... | |
| Mass | 12/5/2011 |
| Q: What is a mass(confused with definition of mass)? How it is measured? Is there any special apparatus ... A: Mass is measured in kg, weight in Newtons. Weight = mg where g is the acceleration due to gravity ... | |
| Voltage | 11/29/2011 |
| Q: My last science class was in 1975! So I've forgotten even basic things. Last year I had problems ... A: Lights can be wired in either series or parallel. If a group of lights all go out, they're in ... | |
| Is dangerous electricity going through my pets?? | 11/26/2011 |
| Q: and thanks for your availability for this odd question. OK, here goes: I have an adorable dog and ... A: First of all, a joule is a measure of energy equal to a watt-second. In other words, if the warmer ... | |
| 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: Well, of course everything has to obey the laws of physics. As soon as the arrow or bullet leaves ... | |
| physics | 11/12/2011 |
| Q: "sir my question is that which will dissipste more power when load is connected in series or ... A: Assume you have two resistances in series and two resistances in parallel for the same voltage. For ... | |
| Electric and Magnetic Fields | 11/8/2011 |
| Q: I have heard about the Electric and the Magnetic Fields created by the Over Head high tension power ... A: Both electric and magnetic fields are proportional to 1/r, the distance from the wires. Electric ... | |
| Combined Pull | 11/1/2011 |
| Q: Why doesn't the moon crash into the earth when the earth is between the moon and the sun ? Two ... A: The gravitational force between two objects is given by F = Gm1m2/r^2 where m1 and m2 are the two ... | |
| Physics - electrostatics | 10/18/2011 |
| Q: Three point charges 2mC, -4mC and 6mC are held at the corners of an equilateral triangle with sides ... A: First of all, I figured that mC means microcoulombs and not millicoulombs. Force F12 is 80N ... | |
| Electric potential | 10/4/2011 |
| Q: Give examples of situations in which the potential of a charge body has a sign opposite to that of ... A: 1. Lightning usually strikes the highest point so that's why you crouch. With both feet touching, ... | |
| Velocity question | 10/3/2011 |
| Q: I'm not a student, but a 54-year-old fan of NHRA racing. I hope you don't consider this frivolous ... A: Since S (distance) = (1/2)at^2, 1000 = (1/2)a(3.769)^2 and a (acceleration) = 140.79 ft/s. If he ... | |
| neutrinos | 9/24/2011 |
| Q: I am an expert at Allexperts in the biology category but am interested in particle physics. ... A: You have to realize that there's a lot of empty space in our bodies since we're made up of atoms ... | |
| polarization, | 9/16/2011 |
| Q: I have been visiting several sites on light polarization.But first a question,sound waves and other ... A: A transverse wave, like light, vibrates in all directions perpendicular to the direction of motion. ... | |
| Ref: question | 9/11/2011 |
| Q: Good day Why is it that the atom is mostly empty space and what is the implications of this? Also ... A: You have to accept nature as it is. The atom is made up of protons and neutrons in the nucleus and ... | |
| Thermodynamics | 9/10/2011 |
| Q: Sir, Far above the Earth's surface the gas kinetic temperature is reported to be on the order of ... A: freeze at 1000K? not likely. I would not expect the composition to change significantly with ... | |
| circular motion = acceleration ? | 9/9/2011 |
| Q: circular motion = acceleration ? A piece of mass falling is defined by (mass x acceleration). Is a ... A: acceleration has units of length/time^2 such as meters/second^2 There's no such quantity as ... | |
| Electric field and Thermosynamics | 9/8/2011 |
| Q: Sir, 1. A point charge q of mass is released from rest in a nonuniform field. (a) Will it ... A: 1. electric field lines are lines of force unless you're talking about equipotential lines. 2. You ... | |
| Electric field and Thermosynamics | 9/8/2011 |
| Q: Sir, 1. A point charge q of mass is released from rest in a nonuniform field. (a) Will it ... A: 1. What do you mean by "line of the force"? The charge will be influenced by the electric field, ... | |
| Electrostatic | 9/7/2011 |
| Q: Sir, The quantum of charge is "e" (Charge of electron). Is there a corresponding quantum of ... A: The standard units for mass, length and time are kilograms, meters and seconds. In addition, there ... | |
| Physics | 8/28/2011 |
| Q: Okay so I have a homework problem that I have no idea how to even START on it. I am not asking for ... A: Draw a portion of a circle and draw a line for the radius from the center to the edge. Draw another ... | |
| electromagnetic waves | 8/27/2011 |
| Q: I understand em waves consist of both a electric and magnetic field which stimulate each others ... A: Em waves consist of electric and magnetic components that vibrate perpendicularly to each other. ... | |
| about the difference between electric and magnetic field | 8/19/2011 |
| Q: when a current is passed through the magnet, magnetic field is produced. But flow of current is ... A: Charged particles such as electrons have an electric field surrounding them whether they are moving ... | |
| Destruction of mass | 7/30/2011 |
| Q: A conservation law says mass can't be created or destroy. Einstein in his famous equation, says ... A: Yes, mass plus energy is conserved. In a fission or fusion reaction, the missing mass doesn't ... | |
| Human Being Resistance Power. | 7/30/2011 |
| Q: Human Being Body is a Good Conductor of Electricity (consists of watery fluids) since Water is good ... A: First of all, water is not a good conductor of electricity. It's conducted because of ions in the ... | |
| Destruction of mass | 7/27/2011 |
| Q: A conservation law says mass can't be created or destroy. Einstein in his famous equation, says ... A: That conservation law no longer applied once fission was discovered. When a U-235 atom is hit by a ... | |
| Momentum | 7/26/2011 |
| Q: Momentum means "total energy of body" please explain about it. Thank you A: I've never heard it defined that way. Momentum doesn't have units of energy. Objects can have ... | |
| simple pendululum | 7/24/2011 |
| Q: Nice day,, -if a pendulum clock is accurate at sealevel,predict whether it will lose or gain time ... A: There's no way that we can ever travel near the speed of light. It would take too much energy. The ... | |
| PHYSICS | 7/21/2011 |
| Q: A spring-loaded toy gun is used to shoot a ball of mass m=1.50kg straight up in the air, as shown in ... A: Since both masses are the same, the first object will stop and the second object will continue along ... | |
| Ice in Water | 7/14/2011 |
| Q: A single 50 g ice cube is dropped into a thermally insulated container holding 200 g of water. The ... A: (c) To keep it simple, I'll just use 2.5 degrees. To cool the water down to 0 degrees you have to ... | |
| physics | 7/4/2011 |
| Q: at 62 mph hitting a 120lb.human would send subject what distance in feet.subject being stationary. ... A: Physicists prefer to work in metric units. 62mph = 91m/s, 5000 lbs = 2273 kg, 120 lbs = 54.5 kg ... | |
| electricity | 6/29/2011 |
| Q: Hey Richard, When electrons move from high to lower potential in DC current is produced.In AC the ... A: An electrical current is defined as a movement of charge. One ampere = one coulomb/second. ... | |
| power needed for flight | 6/28/2011 |
| Q: I am 14, and in grade 10. I would like to know: 1. How much power in watts is needed to lift 300 ... A: You need to know that physicists prefer to work with metric units, like watts. 300 pounds = 136 kg ... | |
| Tunning Fork | 6/28/2011 |
| Q: Can you help me with this problem? A tunning fork with frequency f = 512 Hz is held by someone who ... A: The frequency of sound changes if the source is moving toward or away from you. It's called the ... | |
| tension in ropes | 6/28/2011 |
| Q: Suppose that 2 balls are hung by 4 ropes, 2 for each ball. One ball is hung by 2 ropes fastened at ... A: Let's assume the angles are both 2A. If you draw the force diagrams, in both cases, 2TcosA = mg. So ... | |
| physics | 6/23/2011 |
| Q: How far could a 750lbs motorcycle spin a 3000lbs car if it hit car on left rear fender travling at ... A: The velocity of the car doesn't matter. The motorcycle at that velocity would have a lot of ... | |
| physics | 6/23/2011 |
| Q: why current flows through a conducting wire.............if potential at every point on it is ... A: I presume you know that opposites attract. The north pole of a magnet attracts a south pole. A ... | |
| Physics | 6/22/2011 |
| Q: There is a similar question on this website reffering to a lorry traveling at 50kph and braking on ... A: The coefficient of friction depends on the two surfaces. There are some tables of values but ... | |
| 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: As I mentioned, locomotives are made to run at full speed in either direction since it's not always ... | |
| Ramps, Springs, and Friction | 6/16/2011 |
| Q: A physics student pulls a block of mass m = 25 kg up an incline at a slow constant velocity for a ... A: Don't you understand about significant figures? You only have data good to 2 significant figures. ... | |
| Loops and Radius | 6/16/2011 |
| Q: A cart slides down a frictionless inclined track to a circular loop of radius R = 13 m. In order for ... A: (a) that's the answer I would give so I don't know what they mean about different conditions. yes, ... | |
| Questions abt Astronomy and Physics | 6/12/2011 |
| Q: )I come from Hong Kong and my name's Veronica.Im studying in year7. I heard that the world began ... A: It's not true that energy cannot be created or destroyed. Haven't you heard about the atomic bomb? ... | |
| Blocks on Incline | 6/12/2011 |
| Q: A wooden block of mass m = 9 kg starts from rest on an inclined plane sloped at an angle q from the ... A: the acceleration is not 9.81m/s^2. that's for a falling body. in this case S = (1/2)at^2 so 5 = ... | |
| Weights | 6/11/2011 |
| Q: A block of weight wt1 = 446 N sits on a frictionless table of mass 105 kg. The block is connected ... A: First of all, the mass of the table has nothing to do with the solution. The dropping weight ... | |
| Swimmer and Two Dimensional Equations | 6/8/2011 |
| Q: A river 550 ft wide flows with a speed of 8 ft/s with respect to the earth. A woman swims with a ... A: a) for every 4ft across the stream she'll be carried 8ft downstream so she'll end up 1100ft ... | |
| Projectiles | 6/8/2011 |
| Q: A ball is thrown into the air from ground level. After a time t = 2 s, the ball has traveled to a ... A: b) because the y component changes continuously throughout the flight. so you use H = vyt ... | |
| Projectiles | 6/7/2011 |
| Q: At t = 0, an object is projected with a speed v0 = 35 m/s at an angle q0 = 20.6° above the ... A: Okay (a) and (b) c) the vertical velocity = 35sin(20.6) -gt so you were correct for the starting ... | |
| A big "Why" | 5/26/2011 |
| Q: If you have a golf ball falling to earth the earth pulls on it with force "A". The golf ball pulls ... A: 1. Newton's law of universal gravitation states that F = Gm1m1/r^2, where G is a constant, m1 and m2 ... | |
| Optics | 5/15/2011 |
| Q: In Young's Double Slit experiment what will happen to the interference patter on the screen if, a ... A: Green light is defined as having a wavelength between 495nm and 570nm. Blue light has a wavelength ... | |
| Physics, thermodynamics | 5/10/2011 |
| Q: How much time in minutes will it take to heat oil in a insulator from -40 Celsius to 70 Celsius with ... A: That's not the right conversion from kg to quarts. I calculate, for water, 1 quart = 0.947Kg and ... | |
| Physics | 5/9/2011 |
| Q: An object is placed to the left of a convex lens and on the optical axis. The object is 30 cm from ... A: You should have learned that the standard equation for lenses is 1/O +1/I = 1/f so I just put in ... | |
| e=mc2 | 5/5/2011 |
| Q: It is a well known fact that the maximum velocity that can be achieved is C.Then from the equations ... A: c^2 is the conversion factor between mass and energy in a nuclear reaction. As you know, that's a ... | |
| questions | 5/1/2011 |
| Q: I am not a student, but am curious about atoms and electromagnetic waves, how day to day things may ... A: There are electromagnetic waves ranging in energy from gamma rays and x-rays through ultra-violet, ... | |
| photon | 4/28/2011 |
| Q: I just want to clarify my doubts regarding photon. I just learnt about photon and I really had a ... A: A photon is not a unit of energy but it has energy equal to hf, where h is Planck's constant and f ... | |
| Physics | 4/13/2011 |
| Q: An object falls off of a pier and into the ocean (sea water) where it displaces a total volume of ... A: Your friend is completely wrong since you can't multiply volume by 9.8 and get force. If you want ... | |
| Robert Oppenheimer project | 4/11/2011 |
| Q: Hey I'm doing this project for my English class called the Wax Museum, were i have to be a person ... A: A nuclear blast is an uncontrolled nuclear reaction whereby mass is converted into energy. The ... | |
| Physics pendulum | 4/8/2011 |
| Q: Pendulum. A small rock with mass 0.12 kg is fastened to a massless string with length 0.80 m to form ... A: When the rock is raised to its maximum angle, it's 0.2343m above the lowest position. Since v^2 = ... | |
| Physics-law of conservation of momentum | 4/3/2011 |
| Q: When a large truck hits a small car, momentum is conserved. However, the small car experiences a ... A: Mementum is always conserved in any collision so the momentum before the collision equals the ... | |
| Interview for Science Research | 4/2/2011 |
| Q: I want to ask you a few questions for my science research. Please reply as soon as possible. 1. Do ... A: 1. no 2. if you remove electrons a material becomes positive 3. no 4. ... | |
| Physics | 3/21/2011 |
| Q: "Living wood takes in radioactive carbon-14 from the atmosphere during the process of ... A: The count rate is proportional to the number of atoms remaining. The distintegration constant L = ... | |
| Angular Velocity | 3/16/2011 |
| Q: 1. Why isn't angular velocity measured in meters/second instead of radians/second ? 2. If the SI ... A: 1. Because angular velocity is how fast things are rotating. So it's the same at any distance from ... | |
| Energy Speed | 3/15/2011 |
| Q: My Question is 3 folded.(pls do not consider friction) for my self i wanted to understand the real ... A: In scientific terms we don't usually talk about horsepower, but, yes, lifting 75kg 1 meter in 1 ... | |
| Law of radioactive decay | 3/14/2011 |
| Q: I have published this hypothtical paper on scitopics.com and would appreciate if you could solve ... A: It's not fair to say that radioactivity cannot be a continuous process. It's a statistical process ... | |
| Projectile Motion | 3/14/2011 |
| Q: 1. A golfer drives a ball with a velocity of 120 ft/s at an angle f 45 degrees. What is the maximum ... A: 1. So you have an initial vertical velocity of 120sin(45) and a horizontal velocity of 120cos(45). ... | |
| Pysics | 3/9/2011 |
| Q: A 0.19-kg apple falls from a branch 3.5 m above the ground. a) Does the power delivered to the apple ... A: The kinetic energy increases as the apple falls since KE = (1/2)mv^2 and v = gt. Power is the rate ... | |
| angular acceleration | 3/9/2011 |
| Q: what is angular acceleration?how can it be calculated and what is the differences between angular ... A: Linear acceleration is the rate of change of linear velocity with time. Angular acc. is the rate of ... | |
| Physics Question | 3/7/2011 |
| Q: I have this problem that I cannot figure out. I have worked through it with every equation I know, ... A: It's complicated because you have the cart moving linearly [KE = (1/2)mv^2] and you have the axles ... | |
| physics projects | 3/6/2011 |
| Q: I was wondering if you had any physics project ideas relating to tennis on a high school pre-ap ... A: I don't know what "feed off of pace" means. The only thing that comes to mind about tennis is ... | |
| physics help | 3/4/2011 |
| Q: I have this assignment with this question included and do not understand it at all. Could you please ... A: I used w for angular velocity since the actual symbol is the Greek letter omega. 1 Hz = 1 ... | |
| physics help | 3/3/2011 |
| Q: I have this assignment with this question included and do not understand it at all. Could you please ... A: You need several equations. w(ang. vel) = 2(pi)f = 2(pi)(2.4) = 15.08rad/s I(moment of intertia) = ... | |
| Physics - Electromagnetism | 3/2/2011 |
| Q: An electric power station is producing 1.6 x 10+3 W of power that is to be sent to a small town ... A: I hope you realize that 1.6x10^3 watts is about the amount used by a small portable heater, not the ... | |
| Physics | 2/28/2011 |
| Q: Suppose a bow has an effective spring constant of 450 N/m. if you draw back a 25-gram arrow .5 m and ... A: Where did you get this question? I answered another one with the same energy last week. a) PE = ... | |
| Kinetic Energy and Projectile Motion | 2/27/2011 |
| Q: The initial kinetic energy imparted to a 0.98 kg bullet is 1065 J. The acceleration of gravity is ... A: Where did you get this question? I got the same conditions from Sabah except he wanted to know the ... | |
| Basic Physics Help and Explain | 2/25/2011 |
| Q: ) Resolve a force of 100N acting at an angle of 37degrees with the horizontal into horizontal and ... A: Problems 1-3 just use trig to calculate components. Problem 4 is just a triangle with sides 250 ... | |
| Phyics | 2/22/2011 |
| Q: I have several questions.I need help solving these problems. here they are: 1). A ball on the end of ... A: 1) a = v^2/r = 4^2/0.72 = 22.22m/s^2 Tension at top = 0.3(22.22-9.8) = 3.73N Tension at bottom = ... | |
| weight | 2/18/2011 |
| Q: why it is tiring to hold a heavy weight even though no work is don? ANSWER: Your body is expending ... A: First, sugar to a kilogram. It would be the same either place since kg is a unit of mass. ... | |
| physics | 2/17/2011 |
| Q: Richard, Consider a 7-Kg ball with a radius of 0.9m and rotating about an axis passing ... A: You have the information right there to answer your first question, 50(80) = 4000 calories. Take ... | |
| Acceleration | 2/17/2011 |
| Q: A ball falling is a Force. F=mA When the ball hits the earth, where does the "A" go ? If the ball ... A: Newton's Law of universal gravitation states that F = Gm1m2/r^2. If m1 is the Earth, ME, and m2 is ... | |
| Physics - Circular Motion | 2/16/2011 |
| Q: A motorcyclist is riding on vertical walls on a cylindrical track. What are the forces acting on him ... A: There's a force due to gravity acting straight down. There's a centrifugal force due to his ... | |
| physics with trig | 2/11/2011 |
| Q: An archer stands on a cliff that is 100 m high, shooting at a mark on the ground below 430 m away ... A: 100 = (1/2)gt^2 so an arrow shot horizonally would hit the ground in 4.52s. In that time it would ... | |
| velocity | 2/9/2011 |
| Q: Can you tell me how to figure this out. The question doesnt make sense to me so I am not sure ... A: Let's suppose you're going to fire someone from a cannon that is aimed 30 degrees above the horizon. ... | |
| power | 2/7/2011 |
| Q: why it is tiring to hold a heavy weight even though no work is don? ANSWER: Your body is expending ... A: Talking about an energy crisis is really talking about sources of fossil energy such as coal and oil ... | |
| Ray optics (first year university) | 2/6/2011 |
| Q: This question is from a first year university physics course. I'll give the details of the question ... A: Rays don't exist except as a way to find where the image is on a diagram. The graph isn't exactly ... | |
| Physics | 2/5/2011 |
| Q: Harry stands a distance of 2.91 m directly in front of the midpoint between two speakers. The ... A: (a) you could draw triangles and calculate this. To the nearest speaker, distance = [2.91^2 ... | |
| Kinematics 12th grade | 2/5/2011 |
| Q: If someone throws a rock horizontally off the edge of a 70 m cliff and it lands 100 m from the base ... A: Use S = (1/2)gt^2 to find the time it takes for the rock to hit the ground, so 70 = (1/2)(9.8)t^2 ... | |
| physics | 2/4/2011 |
| Q: Richard,I have been workin on this problem for 45 minutes and still can't get it right. A wheel has ... A: The symbol for angular velocity is the Greek letter omega and I'll use w. The symbol for angular ... | |
| velocity | 2/3/2011 |
| Q: does a freely falling body variable or uniform acceleration? A: A body starts falling with an acceleration g, due to gravity. However, if the body falls quite a ... | |
| Physics | 2/3/2011 |
| Q: 1) Find the energy km/hr consumed in 10hr by four devices of power 500wt each? 2) Certain force ... A: 1) km/hr is not a proper unit. do you mean kwh? If so, the answer is 20. 2) (1/2)(20)(5^2-2^2) = ... | |
| physics | 2/2/2011 |
| Q: Starting from a rest, a railroad car rolls down a hill 20 m high and hits another identical car at ... A: The collision is inelastic and does NOT conserve energy. The first car has a velocity of 19.8m/s ... | |
| Potential and Kinetic Energy | 2/1/2011 |
| Q: Hey Richard! I am doing a science fair project on potential and kinetic energy. Do you have any ... A: You could try dropping something 5-10 meters and timing it. The velocity = gt. With the velocity ... | |
| definition of net energy loss | 1/30/2011 |
| Q: I'm looking for a verification of a general definition for net energy loss. The definition as I ... A: I think what you mean is that no process is 100% efficient. The laws of thermodynamics prevent us, ... | |
| Resistors and batteries | 1/29/2011 |
| Q: “I'm working on understanding resistors; do they produce a voltage drop or a current drop? So ... A: A battery produces energy which can cause electrons to flow through a circuit. Resistors are so ... | |
| physics hw help | 1/29/2011 |
| Q: I have a couple of questions: 1. A solid cylinder with a mass of 28.0 kg and a radius of 0.55m ... A: 1. The potential energy lost by the cylinder = kinetic energy gained so mgh = (1/2)mv^2 = ... | |
| Physics | 1/26/2011 |
| Q: When two charged objects are close together, an electrostatic force is generated. What is the ... A: the magnitude is given by F = kq1q2/r^2 where k = 9x10^9, q1 and q2 are the charges in coulombs, and ... | |
| 19/Introductory Physics-Vectors | 1/26/2011 |
| Q: The x & y components of a vector r and rx = 14 m and ry = -9.5 m. Find the direction & magnitude of ... A: Think of the vectors as two sides of a right triangle and you need to find the hypotenuse so r = ... | |
| Physics HW Question | 1/22/2011 |
| Q: Chttp://www.allexperts.com/user.cgi?m=4&expID=65270&catID=1358onsider the following figure. (The ... A: (a) F(q1,q2) = 9x10^9(1.04x10^-6)(2.27x10^-6)/0.1^2 = 2.125N to the right F(q1,q3) = 0.973N up ... | |
| Physics HW Question | 1/21/2011 |
| Q: An electron is near a positive ion of charge +9e and a negative ion of charge −8e (see the ... A: Force between charges = kq1q2/r^2 (a) the force of attraction between the electron and the +9e ... | |
| Gravity and Gravitation | 1/21/2011 |
| Q: I am a grade 6 student, and I am doing research for my science project. I will give you credit for ... A: You can look up gravitation in the dictionary so I don't have to type it out. Every object that has ... | |
| Physics HW Question | 1/21/2011 |
| Q: I'm sure this is a very simple answer but I am just not understanding what its asking me to solve ... A: The force between two charges is given by F = kq1q2/r^2 where k = 9x10^9 and q1 and q2 are the ... | |
| What if the bob of a simple pendulum becomes heavier? Will its period increase, decrease or remain the same? | 1/19/2011 |
| Q: If not, what are the factors that affect the period of a simple pendulum? Can the factors include a ... A: By definition, the period of a simple pendulum is not affected by the mass of the bob nor by the ... | |
| Physical Optics | 1/18/2011 |
| Q: 1.In a double-slit experiment using monochromatic light, the slits are 0.025 mm and a screen is ... A: I'm going to use L for lambda (wavelength) and A for the angle. (1)(a) dsinA = mL so ... | |
| Physics | 1/18/2011 |
| Q: Actually, what does it mean by loop current in the circuit?? ANSWER: I've tried to explain to you ... A: This is the last time I'm going through this since I have other students waiting for answers. Do ... | |
| Physics | 1/18/2011 |
| Q: Actually, what does it mean by loop current in the circuit?? ANSWER: I've tried to explain to you ... A: Exactly. Since I chose the directions of the loop currents to be clockwise, the branch current ... | |
| Physics | 1/18/2011 |
| Q: Actually, what does it mean by loop current in the circuit?? A: I've tried to explain to you that it doesn't mean anything. It's just a convenient way to solve the ... | |
| Physics | 1/17/2011 |
| Q: er, can you give an example to differentiate between the two methods (loop current method and branch ... A: The object is to calculate the currents. I1 and I2 are both loop currents and so they both flow ... | |
| Physics | 1/17/2011 |
| Q: Can you please help? A river flows due east at 1.50 m/s. A boat crosses the river from the south ... A: (a) v = (10^2+1.5^2)^1/2 = 10.11187m/s (ordinarily I wouldn't include that many sigificant figures ... | |
| Reflection from water | 1/17/2011 |
| Q: Perfectly clear, calm water of any depth will reflect exact, precise images.How does this happen ?? ... A: The surface simply acts like a mirror. It's not that I don't like that type of question. It's ... | |
| Physics | 1/16/2011 |
| Q: I do not know where or how to start working on this, can you assist A fireman 50.0m away from a ... A: the horizontal velocity of the stream is 40cos(30) = 34.64m/s. the initial vertical velocity of the ... | |
| Physics | 1/15/2011 |
| Q: What's the difference between the two method, solving by using loop current and branch current? ... A: Okay, assume there are 3 branch currents so you pick a direction for each. If you pick the wrong ... | |
| Physics | 1/15/2011 |
| Q: Could you help me with exercise 21.5 Q1?? I dont get the way to solve for the ques and I havent ... A: Just for the purposes of working the problem, assume there's one current that circulates through the ... | |
| Physics | 1/14/2011 |
| Q: Could you help me with exercise 21.5 Q1?? I dont get the way to solve for the ques and I havent ... A: There are two ways to work problems like this, with branch currents and loop currents. Since there ... | |
| Physics question | 1/14/2011 |
| Q: Two forces are applied to a tree stump to pull it out of the ground. Force F (with ->) above, and a ... A: Your explanation was good enough. You didn't need the ->. Resolve the first force into its x and y ... | |
| Physics | 1/13/2011 |
| Q: First of all, I want to get myself to understand why current in series circuit is the same while in ... A: In a series circuit there may be several resistances. Since V = IR and the current is the same ... | |
| Physics | 1/13/2011 |
| Q: First of all, I want to get myself to understand why current in series circuit is the same while in ... A: Current is due to the flow of electrons in a conductor. A series circuit is a loop and there's no ... | |
| high school physics | 1/13/2011 |
| Q: student is dragging a 5 kg box along the floor. He pulls on the rope with a 25 Newton force. The ... A: The 25N force has a 20N horizontal component and a 15N vertical component. The normal force = ... | |
| Physics | 1/11/2011 |
| Q: Can you do a break down (step by step) on how I can solve this? On a 220 km trip, a person wants to ... A: That's easy. Since time = distance/velocity, at an average speed of 61.7km/h, the total time for ... | |
| physics | 1/11/2011 |
| Q: sir I am a student of class xii.I request you to kindly solve the following"There are five balls ... A: I don't believe it's possible. 1 &4 have to have the same charge, as do 3 &5. so you have four ... | |
| moments | 1/11/2011 |
| Q: The diagram shows a gauge which measures the amount of liquid in a tank. Where should the pivot be ... A: You can prove it with angles. With the pivot at D, the angle the pointer makes by going from F ... | |
| Physics | 12/29/2010 |
| Q: and my class did a lab experiment on resonance thermometers. We were given two tunng forks, one at ... A: Thermometers measure temperature. You don't fill them with water. I presume you were using ... | |
| nuclear physics | 12/23/2010 |
| Q: What are main differences between beta particle and electron? is there difference between ionization ... A: Beta particles and electrons have the same mass. Electrons go around the nucleus of an atom in ... | |
| lens | 12/19/2010 |
| Q: why convex lens converges and concave lens diverges? ANSWER: To learn all about lenses go to ... A: I assume you're familiar with the refraction of light. When a light wave hits a surface at an ... | |
| Radio waves | 12/19/2010 |
| Q: Can a lens refract and converge radio waves? If yes, how much diameter should have a glass lens to ... A: glass lenses cannot refract radio waves. radiotelescopes can focus radio waves coming from outer ... | |
| Physics/Force | 12/15/2010 |
| Q: A ball on a tess is at rest, it has a mass of 2kg. A boy swings and hits the ball, after 4 seconds ... A: To be accurate, you would need to know the time that the club and the ball were in contact since Ft ... | |
| Physics | 12/8/2010 |
| Q: (1) If the weights of the weight hangers were exactly the same could their weights have been ... A: (1) That's called a force table and is a standard experiment in general physics. You cannot neglect ... | |
| Plane of polarisation of EM wave | 11/27/2010 |
| Q: What does it mean by the plane of polarisation of an electromagnetic wave describes the plane of ... A: The electric fields and the magnetic fields in an EM wave oscillate at right angles to one another. ... | |
| how much metal has to be present for an electromagnet to attract it? | 10/7/2010 |
| Q: I have a question about magnetic attraction. If I have an electromagnet and want to use this to ... A: Yes, size makes a difference, although even small pieces of metal would be attracted. They use ... | |
| Physics | 10/6/2010 |
| Q: A physics book slides off a horizontal table top with a speed of 2.8 m/sec. It is observed to ... A: I'm on vacation and don't have a calculator with me so you will have to complete the calculations. ... | |
| Horizontal kinematics | 9/19/2010 |
| Q: This question has me stumped. The fact that there is no time value is really confusing me. Two cars ... A: 72km/hr = 20m/s. Assume the origin of time is the moment the driver of car B notices Car A behind ... | |
| Physics | 9/15/2010 |
| Q: 7. A 1000 kg car whose speed is 80 km/h (22.2 m/s) has a kinetic enrgy of? A. 25.2 kJ B. 247 kJ c. ... A: Don't you understand that KE = (1/2)mv^2? 7. KE = (1/2)(1000)(22.2)^2 = 2.46x10^5J (B) 8. 1 = ... | |
| Physics | 9/14/2010 |
| Q: * In an isolated system, momentum does not change. For example, when a bowling ball hits a rolling ... A: Momentum is conserved in any collision. Because the mass of the bowling is much greater than the ... | |
| Motion in a plane | 9/13/2010 |
| Q: A tennis ball rolls off the edge of a tabletop 0.900m above the floor and strikes the floor at a ... A: The time to hit the ground is simply based on the distance falling, so 0.9 = (1/2)(9.8)t^2 and t = ... | |
| Physics help.. | 9/11/2010 |
| Q: I hope you can help me with these questions, 1} (a)What expalanation is used today to explain how ... A: 2)(a) 60 watts is correct (b) 1000/60 = 16.67 hours (c) 166.67 hours 3) F = ... | |
| Horsepower Question | 9/9/2010 |
| Q: I completed an experiment on human horsepower by timing volunteers walking and running up the ... A: There's no limit to the height of the stairs. However, since power is the time rate of doing work, ... | |
| Nuclear | 9/5/2010 |
| Q: A nuclear reactor may contain a carbon moderator and boron steel control rods. What are these for ... A: When you split that U-236 atom and get two neutrons out you want one of the neutrons to hit ... | |
| Nuclear | 9/5/2010 |
| Q: What is the difference between nuclear fusion and nucear fission? I would just like to know many ... A: Fission primarily occurs with uranium and plutonium. If you hit a U-235 atom with a neutron and it ... | |
| Environmental Physics | 9/4/2010 |
| Q: I am having trouble setting up this problem, it's probably pretty easy because I got through all ... A: At half the distance from the sun, the solar intensity would be four times greater, or 5.4kW/m^2. ... | |
| Force in kg's | 9/3/2010 |
| Q: "Is this calculation correct if I use F=m*a formula for this case? - soccer ball weights 0,4 kg - it ... A: The velocity is constant so there's no acceleration. velocity = distance/time = 10/0.5 = 20m/s So ... | |
| physics | 8/26/2010 |
| Q: At a county fair there is a betting game that involves a spinning wheel. As the drawing shows, the ... A: 0.115 rev/s^2 = 0.7226rad/s^2, 1.52rev/s = 9.55rad/s, 2.55rev/s = 16.02rad/s (a) time = 9.55/0.7226 ... | |
| electricity and magnetism | 8/18/2010 |
| Q: a) 5.2uC b)4.6nC c)3.0pC d)3.5x10^-3uC how would i convert these into coulombs? and what does ... A: uC is an abbreviation for microcouloumbs or 10^-6 coulombs. It really is supposed to be the Greek ... | |
| Nuclear Explosion | 8/18/2010 |
| Q: I seem to be a little confused on the difference between a critical accident and a nuclear ... A: When you split the atom, U-235, or Pu-239, you get, on the average, two neutrons out. In the case ... | |
| physics | 8/9/2010 |
| Q: solve using quadratic formula : x^2-2x+2=0 ANSWER: x = [2 +/-(-4)^1/2)]/2 = 1 +/-i ---------- ... A: a) That's one of the Lagrangian points. If x is the distance from Earth, then 1/x^2 = ... | |
| Collision | 8/2/2010 |
| Q: I'd like to know the governing formula of two falling object that contact to each other in air to ... A: If the masses are m1 and m2, the velocities before collision are v1 and v2, and the velocities after ... | |
| Engineering Science | 8/1/2010 |
| Q: A complex waveform is described by the equation: v= 100sin(100πt)+50sin(200πt-π/2) ... A: You have the sum of two sine waves. You can sketch it out by picking some simple value for n, like ... | |
| Life | 7/31/2010 |
| Q: i am just curious about life as we know it, yesterday i had a very peculiar life awakening ... A: I appreciate being called one of the great minds, but I'm just a lowly physical scientist, 78 years ... | |
| Nuclear bomb in space vs in air | 7/26/2010 |
| Q: Based on the premise that neutrons are the primary cause of a chain reaction, is the "explosive " ... A: When the first atomic bomb was set off at the Trinity site July 16, 1945, a few scientists were ... | |
| Help with setting up a ball rolling down incline question | 7/15/2010 |
| Q: I am helping someone with aA solid sphere is rolling without slipping or sliding down a board that ... A: Even though your calculator gives you 9 digits, you never want to record more than 3 or 4 of them. ... | |
| Help with setting up a ball rolling down incline question | 7/14/2010 |
| Q: I am helping someone with aA solid sphere is rolling without slipping or sliding down a board that ... A: You have to take into account the moment of inertia of the sphere, I = (2/5)mR^2 If F is the ... | |
| Physics | 7/12/2010 |
| Q: 1.How would the force arrow in a diagram representing gravity (or weight) vary for an object at free ... A: 1. The weight of an object is the same whether at rest or in free fall. It falls with a constant ... | |
| Physics | 7/11/2010 |
| Q: In a multiple choice question based on a graph, there are two options that I think mean the same ... A: Since I can't see the graph I don't know how to interpret it. If you know what the error is then ... | |
| rainbow | 7/8/2010 |
| Q: sir this is a question regarding rainbow I know how a rainbow is formed due to total internal ... A: You have probably noticed that the sun has to be behind you in order for you to see a rainbow. Not ... | |
| physics | 7/5/2010 |
| Q: 1. A rope 26 ft long is attached to two points A and B, 20 ft apart at the same level. A load of ... A: 1. The rope makes an angle of 39.715 degrees with the horizontal. The tension in the rope (same as ... | |
| telescopes moon arc diameter in the earth sky | 7/1/2010 |
| Q: Well I'm basically trying to understand a bit more the Dawes limit equation. But it keeps referring ... A: An arc is simply a portion of a circle. A circle has 360 degrees. A degree has 60 minutes and a ... | |
| Physics-Electric forces and coulomb's law | 6/30/2010 |
| Q: Three charges with q = +3.7 µC are located as shown in the figure ... A: (a)The distance from each of the charges to the bottom charge is 0.18(2^1/2) = 0.2546m The force ... | |
| Significant Figures | 6/29/2010 |
| Q: age=17 Class= none (independent studies) If a train travels 890 km from Berlin to Paros and then ... A: You can use it in this case to calculate percentage, but you would never say that the train traveled ... | |
| physics | 6/25/2010 |
| Q: Roberta drives her 1452 kg car along a straight , level road at a constant velocity of 30.0 m/s [E]. ... A: 1. v = v0+at so 25 = 30+a(25) and a = -0.2m/s^2. 2. F = ma = 1452(0.2) = 290N 3. 0 = 25+a(3) so a ... | |
| Time, Speed and Distance | 6/24/2010 |
| Q: Firstly, I am not requesting you to solve a text book problem. In fact, I could not really ... A: To get the average speed you have to divide the total distance by the total time. You cannot ... | |
| physics | 6/2/2010 |
| Q: A car starts from rest and accelerates uniformly at a rate of 4.0 m/s^2 East. At the same instant, a ... A: a) S = (1/2)at^2 = (1/2)(4)(10^2) = 200m b) S = vt = (25)(10) = 250m c) 312.5 = (1/2)(4)t^2 so t = ... | |
| learning Physics | 5/27/2010 |
| Q: I'm a student and i need some advice regarding learning physics. I have a lot of difficulty doing ... A: As I said before, you just have to keep at it. Physics involves a lot of math, mostly algebra. ... | |
| atrophysics | 5/23/2010 |
| Q: Is there one or more types/forces of gravity? some planets do not have electric magnetic fields (as ... A: Gravity is a function of mass. It has nothing to do with magnetic fields. Newton's Law of ... | |
| Hydrogen and electricity | 5/20/2010 |
| Q: lately I've been thinking a lot about getting electricity from hydrogen and I was wondering how much ... A: There's not an easy answer. When you combine hydrogen with oxygen you get heat energy plus water. ... | |
| kinematics | 5/18/2010 |
| Q: Determine a safe driving distance rule using kinematics (assume a decceleration rate of about 4.5 ... A: 10, 20 and 30 mph = 4.47, 8.94, 13.41m/s since v^2 = 2aS, for a = 4.5m/s^2, S = 2.22, 8.88 and 20m ... | |
| Atoms | 5/17/2010 |
| Q: do you think that the world is a better place now that we know the structure of atoms or has it ... A: I live in Oak Ridge, TN, where they processed the uranium for the atomic bomb that was dropped on ... | |
| atoms | 5/16/2010 |
| Q: Is it a positive or a negative that our knowledge of the atom is increasing? Are there factors that ... A: Are you and Ryan and Isabella all in the same class? Since everything is made of atoms it's not ... | |
| light and other waves | 5/9/2010 |
| Q: Newton says a thing moves in a straight line if not affected by forces. Why doesn't light or sound ... A: the amplitude is a function of the energy associated with light or sound. light travels in a ... | |
| conservation of energy - internal energy | 5/3/2010 |
| Q: A worker drives a 0.500 kg spike into a rail tie with a 2.50 kg sledgehammer. The hammer hits the ... A: The hammer has a KE of (1/2)mv^2 = (1/2)(2.5)(65^2) = 5281J and a third of that would be 1760J. ... | |
| question about being a physicist | 5/3/2010 |
| Q: my name is Stephan. I am a 14 yrs old 9th grader in Whitney High. For a school project, i need to ... A: I am 78 years old and retired. I got a BA in math, an MA in physics, and a PhD in physical ... | |
| mixture temp | 5/2/2010 |
| Q: can u please tell me any formula 2 find the temperatre of mixture when 1) ice and water are mixed 2) ... A: let I = mass of ice, W = mass of water, S = mass of steam Si = specific heat of ice, Sw = specific ... | |
| mechanics | 5/2/2010 |
| Q: Frictional force always acts opposite to the motion to the body then how come it provides the ... A: There are actually two frictional forces acting. There is one tangentially or else the tires would ... | |
| mixture temp | 5/2/2010 |
| Q: can u please tell me any formula 2 find the temperatre of mixture when 1) ice and water are mixed 2) ... A: In each case the heat gained by the ice is equal to the heat lost by the water or steam. If the ... | |
| Two part Physics equation | 4/27/2010 |
| Q: A person of mass 100kg is swinging on a rope-swing (length=8 feet). The person swings back and ... A: 8cos(30) = 6.93 so at max. height the person is 1.07ft above the bottom. v^2 = 2gh so v^2 = ... | |
| Dynamics + Forces (grade 12) | 4/27/2010 |
| Q: Can You help me, please, with the following questions?! P.S. These question came from Unit review ... A: 1) I don't know why vf=vi+at doesn't give you the right answer, that's vf=12+0.15(95) = 26.25m/s 2) ... | |
| 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: 1) I like to say science is the study of our surroundings. 2) They figured out that we see things ... | |
| entropy | 4/2/2010 |
| Q: I am a happy science amateur (38 years old), who likes to read popular science books. For the sake ... A: There's another way to look at entropy. It's a measure of the order of the system. There's only so ... | |
| physics | 3/29/2010 |
| Q: A baseball (m = 135 g) approaches a bat horizontally at a speed of 39.1 m/s (87 mi/h) and is hit ... A: 1) v^2 = 2gH = 2(9.8)(1.1) so v = 4.64m/s 2) v^2 = 2gH = 2(9.8)(136)sin(12) so v = 23.5m/s 3) (a) ... | |
| physics | 3/29/2010 |
| Q: A baseball (m = 135 g) approaches a bat horizontally at a speed of 39.1 m/s (87 mi/h) and is hit ... A: (1) the ball hits the floor at 6.18m/s and rebounds at 3.43m/s. so impulse = 0.280(6.18+3.43) = ... | |
| Gravitational constant and G | 3/26/2010 |
| Q: I have two question who are similar: 1. What is the difference between Gravitational constant and ... A: 1. Newton's Law of Universal Gravitation is F = Gm1m2/r^2 where m1 and m2 are two masses and r is ... | |
| Please can you help me | 3/22/2010 |
| Q: How are you? I have this assignment question but i am really battling with the course material. Do ... A: Q1 The decay constant = 0.693/half-life = 7.55x10^-10/s for Sr-90 The no. of atoms = ... | |
| pendulum | 3/21/2010 |
| Q: what is the basic difference between oscillations of a simple pendulum and a compound pendulum A: The difference is calculating the period from the dimensions. For a simple pendulum, such as a a ... | |
| vector addition | 3/12/2010 |
| Q: if we have vector A and B and the angle between theta then A+B= sqrt(A^2+B^2+2abcos(theta)) why does ... A: Let's say you draw the vector B in a horizontal direction, x, and from its tip draw the vector A at ... | |
| aggregation of plutonium dioxide/plutonium in physisorption scenario | 3/12/2010 |
| Q: Really hope you can help as i really need it. you see, my orthopedic recommended me and i did a ... A: If you're worried that you might have gotten a few atoms of Pu along with the Tc-99, you can forget ... | |
| West-East Effect | 3/11/2010 |
| Q: i teach my friends son science as he is home taught, but i am no good a physics, i have a few ... A: Whenever I get a question like this and have never heard of the West-East Effect, I go to the online ... | |
| the nature of energy | 3/9/2010 |
| Q: I am 38 years old and like to think of myself as a fairly advanced layman (I have studied biology, ... A: Very simply, posessing energy means an object has the ability to do work. Kinetic energy is the ... | |
| power surges thru my lamp | 3/9/2010 |
| Q: I don't know if this is the sort of question you can assist with, but I'll give it a go. I have a ... A: There are surge supressors that people use to protect electronic equipment. I have one for my ... | |
| primary color and how it's made? | 3/8/2010 |
| Q: I've read all about the splitting of white light into r/b/y, but how does this equate into a color I ... A: It doesn't equate. Colors of light are entirely different from paints. You can combine colors of ... | |
| physics of boiling | 3/3/2010 |
| Q: What excactly happens when water is boiled? I need to have 250 words on the physics of boiling and I ... A: The boiling point of a liquid is defined as the temperature at which the vapor pressure of the ... | |
| RADIOACTIVITY | 3/2/2010 |
| Q: WHAT IS THE AMMOUNT OF ENERGY PRODUCED BY FISSION AND FUSION? A: the main fission reaction is with U-235. 1 gm of U-235 undergoing fission releases about 2.3x10^4 ... | |
| Physics 1050 -- Undergraduate Physics -- Class of 2011 | 2/28/2010 |
| Q: A .22-caliber bullet is a solid cylinder of length 7.0mm and radius 2.7mm capped at its front with a ... A: For a cylinder, I = (1/2)mr^2, the length doesn't enter in. for a sphere, I = (2/5)mr^2, and you ... | |
| Electric Circuit Analysis | 2/22/2010 |
| Q: First off, I want to tell you that this is not a homework problem. It was, but the assignment is ... A: I put in 3 loop currents, i1, i2 and i3, all clockwise, and wrote 3 loop equations, taking out the k ... | |
| speed of falling objects | 2/21/2010 |
| Q: I have a project due next week and i was wondering if you could tell me at what rate objects fall? i ... A: As you know, if you drop something it falls to Earth. That's because of the force of attraction ... | |
| Help with a concept | 2/17/2010 |
| Q: Hey, I am 20 years old and enrolled in College Physics I. I never took physics in high school and ... A: You need to sum the components of the forces in the east direction. So that's 75cos(38) +54 ... | |
| Question | 2/17/2010 |
| Q: A man of 80kg is standing in the cabin of a Ferris wheel of radius 30m rotating at 1.0 rev/min. What ... A: F = 26.3N is the force due to the rotation of the wheel. At the top it subtracts from the weight of ... | |
| Physics (Sound Waves) | 2/16/2010 |
| Q: just need a little help understanding how to solve: What is the frequency of a tuning fork that ... A: The velocity of sound at 20C is 344.1m/s. Assuming a half wavelength = 20cm = 0.2m, 344.1 = 0.2f ... | |
| Electric Charges, Forces, and Fields | 2/15/2010 |
| Q: I am in the 12th grade. Professor Raridon, I was reviewing this section and I did not know how to ... A: There are three forces acting on each ball, T, the tension in the string, mg, the weight of the ball ... | |
| Physics | 2/15/2010 |
| Q: This s a f0l0w up questi0n about the two lenses, one hvng a f1-10cm and f2=8cm, separated by a ... A: Your first question had the distance between the lenses as 4m and that's the way I worked it. It ... | |
| physics | 1/27/2010 |
| Q: an arrow is shot vertically upward with an initial speed of 30.00 m/s. when its exactly halfway to ... A: The problem isn't as simple as I first thought. Since v = v0-gt, 0 = 30-9.8t, t = 3.0612s which is ... | |
| hello can you help me with this | 1/10/2010 |
| Q: A venturi meter is a device for measuring the speed of a fluid within a pipe. The drawing shows a ... A: Use r for rho. P2 +(1/2)rv2^2 = P1 +(1/2)rv1^2 and A2v2 = A1v1 ... | |
| Tension Problem | 1/10/2010 |
| Q: Here's the question I'm having difficulty with: Two blocks of masses 75 kg and 25 kg are glued ... A: You didn't include a figure but the tension is going to decrease. Initially, the tension is equal ... | |
| please help | 1/10/2010 |
| Q: A paperweight, when weighed in air, has a weight of W = 6.7 N. When completely immersed in water, ... A: If the reservoir contains 4.85x10^5 kg of water and water has a density of 10^3 kg/m^3, then the ... | |
| please help | 1/9/2010 |
| Q: A paperweight, when weighed in air, has a weight of W = 6.7 N. When completely immersed in water, ... A: (6.7-4.8) = mg so m = 0.1939kg = 1.939x10^-4 m^3 When I answered this I assumed that you understood ... | |
| momentum | 12/19/2009 |
| Q: 1.I know that momentum = mass*velocity. But, what it means. Why we're multiplying mass and velocity. ... A: 1. The exact definition of momentum is the product of mass times velocity. It's defined that way ... | |
| Physics | 12/15/2009 |
| Q: Wile E. Coyote decides to try and catch Road Runner. He launches himslef from a cannon at a 33.7 ... A: Does the coyote land on the Road Runner? Range = (v^2/g)sin2A = 81.4m so he misses by 1.4m His ... | |
| physics | 12/11/2009 |
| Q: 1. if a centripetal for is suddenly removed from an objeectm in what direction will then move? 2. ... A: 1. a straight line 2. force times distance 3. 12.6 rad/s 5. in circles around the wire 6. in circles ... | |
| physics in space. | 12/9/2009 |
| Q: I was hoping if you could help me with my questions regarding space probes. I thought asking you ... A: (1) Did you ever go out at night and shine a flashlight up at the sky? Did you notice that the beam ... | |
| pressure and friction | 12/9/2009 |
| Q: Raridon: I am an eighth grader that is preparing for science fair. I am doing an experiment about ... A: Pressure is defined as force per unit area. It is measured with a pressure gauge or by measuring ... | |
| physics | 12/7/2009 |
| Q: Discuss momentum in the context of an elevator and include work done, energy (kinetic energy and ... A: Momemtum = mass times velocity so a moving elevator has a certain amount of momentum. Work = force ... | |
| Lamp Circuits | 12/6/2009 |
| Q: I am 22 years old, sophomore in college. Hello. I am new to the site and I have already cleared up ... A: Just like the length of a wire can change with temperature, so can the resistance. For example, the ... | |
| simple harmonic motion | 12/3/2009 |
| Q: a disc 1m in diameter is cut from a metal sheet the disc is made to swing as a pendulum by drilling ... A: This is an example of a physical pendulum as opposed to a simple one with a weight at the end of a ... | |
| charges | 11/30/2009 |
| Q: why is it logical to say that potential of an earth connected object is zero? what can be said about ... A: There's no such thing as absolute potential. It's always the potential difference between two ... | |
| help please! | 11/22/2009 |
| Q: A 1.90 kg object is hanging from the end of a vertical spring. The spring constant is 39.0 N/m. The ... A: First of all, if you release it at 0.2m down it's not going to go above 0.2m up. In your case, x ... | |
| the "why exactly so?" for the nature of the gravitational force | 11/19/2009 |
| Q: I want to find the answer about the nature of the gravitational force.For which exact reason do 2 ... A: Nobody knows the mechanism. It's just a fundamental property of mass that there's an attractive ... | |
| Energy and Expanding Universe | 11/13/2009 |
| Q: If energy cannot be created or destroyed in the universe, then what does it mean that the universe ... A: The law used to state that energy cannot be created or destroyed but can be changed in form. That's ... | |
| Energy and Expanding Universe | 11/13/2009 |
| Q: If energy cannot be created or destroyed in the universe, then what does it mean that the universe ... A: It's not true that energy cannot be created or destroyed. That changed when fission was discovered ... | |
| What is magnetic force | 11/8/2009 |
| Q: During academic years, we have been taught that a magnet emits lines of force. I'm not not clear ... A: It's hard to describe what you can't see. You just have to visualize them. There is a magnetic ... | |
| Trigonometry | 11/5/2009 |
| Q: I need help with these mister. (NOTICE ABOUT THESE QUESTIONS) Show enough of your work to indicate ... A: 1. 1/2 = 1-2(1/4) = 1/2 2. a. 12(1/2)-(6/2)(2^1/2) +(2^1/2)/52 = b. (3^1/2)/2 +1 -(3^1/2)/2 +2^1/2 ... | |
| What is magnetic force | 11/5/2009 |
| Q: During academic years, we have been taught that a magnet emits lines of force. I'm not not clear ... A: There are field lines surrounding a magnet but they're not really lines of force. The only way to ... | |
| mechanical advantage | 10/30/2009 |
| Q: how do i calculate the mechanical advantage of a simple screw jack? A: It's the distance the end of the lever turns in one revolution divided by the pitch of the screw ... | |
| Physics | 10/30/2009 |
| Q: sketch the electric field lines for -2q and +q charges placed some distance apart. A: I can't sketch it for you. Electric lines go out from a positive charge and terminate at a negative ... | |
| physics | 10/29/2009 |
| Q: Question 1: A 1.5-kg object moves up the y-axis at a constant speed. When it reaches the origin, the ... A: 1. the sum of those forces is -0.975 in the y-direction and 8.975 in the x-direction. (a) no (b) ... | |
| physics | 10/27/2009 |
| Q: Car A hits car B (initially at rest and of equal mass) from behind while going 36 m/s. Immediately ... A: KE before = (1/2)m(36)^2 = 648m KE after = (1/2)m(27)^2 = 364.5m fraction lost = ... | |
| physics | 10/27/2009 |
| Q: A girl of mass m1 = 60 kilograms springs from a trampoline with an initial upward velocity of v ... A: Initially, KE = (1/2)mv^2 = 1920J After 2 meters, PE gained = mgh = 1176J So KE remaining = 744J = ... | |
| infinity in both directions | 10/19/2009 |
| Q: Thinking about infinity radiating outwards from our personal observation point (our eyes and/or our ... A: Sure, there are a lot of small things. That's why they invented microscopes. However, there are ... | |
| Rotation physics | 10/19/2009 |
| Q: A golfer starts with the club over her head and swings it to reach a maximum speed as it contacts ... A: There are two acc. vectors. The acc. vector due to the velocity of the club is going to point ... | |
| Physics Questions | 10/14/2009 |
| Q: "This isn't an assignment. It was a project. My teacher said we can find answers using the net. 1. ... A: Some of these are not physics. I'll answer what I can. 2. the lady with spike heels. pressure = ... | |
| Physical Science (Mechanics) | 10/11/2009 |
| Q: A stone falls from a ledge and takes 16 seconds to hit the ground. The stone has an original ... A: Well, since you should have learned that KE = (1/2)mv^2 = (1/2)(20)(2.8^2) = 78.4J, tell me where I ... | |
| Physical Science (Mechanics) | 10/11/2009 |
| Q: A stone falls from a ledge and takes 16 seconds to hit the ground. The stone has an original ... A: Well, of course I fully understand these questions. I have taught physics and have solved physics ... | |
| Uniform circular motion | 10/7/2009 |
| Q: How does uniform circular motion work? My understanding is that if a car is in an upwards rounded ... A: The car has to follow the curve of the road so it goes in a circular motion. Acceleration means a ... | |
| change in metal compounds. | 10/7/2009 |
| Q: i would like to ask you a brief but specific question about the reactions of metal compounds. by ... A: As you know, uranium has 92 protons and 92 electrons. In addition, U-238 has 146 neutrons in the ... | |
| "Electric Fog" | 10/4/2009 |
| Q: This may sound odd, but I would like a serious answer or I wouldn't bother to ask so... My Ideas on ... A: I can't say that some of those phenomena are not related but I can say that they're not due to very ... | |
| physics problem | 10/4/2009 |
| Q: I'm a junior in highschool taking physics http://www.webassign.net//student.pl?x=6924271253 ... A: Since distance = velocity times time, you need to find the area under the curve for the two time ... | |
| electric potential | 10/2/2009 |
| Q: A parallel plate capacitor is composed of two square plates, 10.0 cm on a side, separated by an air ... A: C = epislon(A/d) = 1.11x10^-10F Q = CV = 16nC If you double the gap the charge drops to 8nC Energy ... | |
| Stress and strain | 9/9/2009 |
| Q: Can you explain what they are in detail and why when 2 thing when hit with the same force even if ... A: Stress is defined as force per unit area, F/A. Strain is what results when a certain stress is ... | |
| physics | 9/8/2009 |
| Q: Calculate the magnitude and direction of the Coulomb force on each of the three charges shown in the ... A: The 6uc charge experiences a force to the left due to the 1.5uc charge and a smaller force to the ... | |
| HELP PLEASE | 9/7/2009 |
| Q: Suppose a 1.0 g nugget of pure gold has zero net charge. What would be its net charge after it has ... A: 1g of gold has (1/196.97)(6x10^23) = 3.05x10^21 atoms Since each atom has 79 electrons, that's ... | |
| physics | 9/7/2009 |
| Q: Two small metal spheres are 25.0 cm apart. The spheres have equal amounts of negative charge and ... A: 1. 0.034 = (9x10^9)q^2/(0.25)^2 so q = 4.85x10^-7 C 2. F = qE = (-6.1x10^-7)(1.1x10^6) = -0.67N ... | |
| physics | 9/5/2009 |
| Q: Three charges are arranged as shown in the picture above. Find the magnitude and direction of the ... A: F(3) = 9x10^9(3x10^-9)(6x10^-9)/(0.707)^2 = 8.1x10^-8N/C F(2) = 5.4x10^-8N/C F(x) = 8.1x10^-8cos(45) ... | |
| physics | 9/4/2009 |
| Q: Case Study: The Case of A Handsome Professor To practice his demonstration of the Law od ... A: Without the naughty student, the pendulum would swing back and nearly touch the professor's nose. ... | |
| physics | 9/3/2009 |
| Q: Calculate the magnitude and direction of the Coulomb force on each of the three charges shown in the ... A: F = kq1q2/r^2 1) F = k(6x10^-6)(1.5x10^-6)/(0.03)^2 -k(6x10^-6)(2x10^-6)/(0.05)^2 = 75-43.2 = 31.8N ... | |
| Electricity | 9/1/2009 |
| Q: when you connect two cells in parallel in a circuit,what is the direction of current ,i mean the ... A: If you simply connected the cells to each other, then what you are saying is true and one battery, ... | |
| mass or no mass | 8/28/2009 |
| Q: Richard, are there particles that contain no mass (by that I mean, is this theory or actually ... A: Photons do not have mass. They are little packets of energy. You have to realize that when we say ... | |
| microwave damage to water | 8/25/2009 |
| Q: I have been told by my friends who are health food believers that you should not use a microwave ... A: If it removed all the nutrients where did they go? Microwave energy is only absorbed by water ... | |
| Young's Modulus of Elasticity related problem | 8/23/2009 |
| Q: A 14.5 kg mass, fastened to the end of a steel wire of unstretched length 1m, is whirled in a ... A: Young's Modulus is defined as (F/A)/(dL/L) where F is the force, A the cross sectional area, dL the ... | |
| light wavelengths | 8/15/2009 |
| Q: I do not understand very much about light or its properties. I was reading about constructive and ... A: When we talk about a red shift from distance stars, the light appears to be shifted because of the ... | |
| light wavelengths | 8/15/2009 |
| Q: I do not understand very much about light or its properties. I was reading about constructive and ... A: Yes, you can mix blue light with yellow light to get a new color. Yes, you can shift wavelengths ... | |
| atom | 8/11/2009 |
| Q: Is gravitational force an electromagnetic force? How this gravitational force get created from an ... A: A gravitational force is entirely different from an electromagnetic force. Any two objects that ... | |
| light | 8/11/2009 |
| Q: What is real and virtual image? And tell me about diffraction, interference and polarisation please. A: Real and virtual images are formed by lenses and mirrors. A real image can actually be formed on a ... | |
| light | 8/1/2009 |
| Q: I've finished my 12th standard. How a rainbow appears in a rain? Is it due to colloidal particles? ... A: You can only see a rainbow after the rain has passed and the sun is at your back at a certain angle. ... | |
| electric current | 8/1/2009 |
| Q: what is the difference b/w E.M.F and terminal potential difference A: An emf is simply a source of energy to keep a current flowing in a circuit. It could be a battery, ... | |
| Speed of Light and Time Space | 7/31/2009 |
| Q: Einstein's major insight, which led him to the Theory of Relativity, was the realization that the ... A: You're getting too philosophical for me. The way I consider it, if time ran backwards, then entropy ... | |
| Speed of Light and Time Space | 7/31/2009 |
| Q: Einstein's major insight, which led him to the Theory of Relativity, was the realization that the ... A: Wow, that's the first time I've ever seen a picture of the person sending me a question. Time is a ... | |
| Physics Problem Solving | 7/25/2009 |
| Q: 1. A 0.40 kg iron horseshoe that is initially at 500 degrees Celsius is dropped into a bucket ... A: In all of these, heat lost = heat gained 1. 0.40(470)(500-t) = 20(4186)(t-22) so t = 23.07 degrees ... | |
| Acceleration in space | 7/24/2009 |
| Q: A golf ball struck by a club on earth is the maximum speed just off the head of the club or does ... A: As soon as the ball leaves the head of the club it accelerates due to gravity. That acceleration is ... | |
| atom | 7/15/2009 |
| Q: I've finished 12th grade. How the nuclear force get created in the nucleus? How this powerful force ... A: Scientists are still trying to figure out the force holding the nucleus together. Gravity is what ... | |
| Gravity | 7/15/2009 |
| Q: I've finished my 12th standard. Our earth behaves like a magnet. Earth can have gravitational field ... A: The Earth has a magnetic field because of its liquid iron core. If you have a spherical magnet or ... | |
| physics | 7/14/2009 |
| Q: .... following is a question in my physics book... The moon is observed from two diametrically ... A: Draw an isoceles triangle with the Earth at the base and the moon at the top. Now draw a line ... | |
| Alternating current | 7/13/2009 |
| Q: explain how the use of transformers improves the efficiency of power transmission. Many thanks A: As current passes through a wire it produces heat according to the relationship I^2R. So the lower ... | |
| 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: It's not the viscosity that would keep you on the surface of the honey, it's the density. You're ... | |
| Regarding the Discharging of a Capacitor! | 7/9/2009 |
| Q: Raridon, I'm having trouble with the following question...It's asked in the analysis part of a lab ... A: 1. So you start with 1000 at time 0. After one hour you take out 10% so you have 900 remaining. ... | |
| Regarding Components, Direction, and Magnitude of point charges! | 7/8/2009 |
| Q: Raridon, 1.) Find the x and y components and the magnitude and direction of the electric field at ... A: I presume you're still talking about the charges at -0.18m and +0.18m. So the distance from each of ... | |
| Battery and Leyden jar | 7/7/2009 |
| Q: What's the difference between battery and Leyden jar? A: the Leyden jar was an early device for storing static electricity by having conductors inside and ... | |
| Regarding electric fiels and point charge! | 7/7/2009 |
| Q: Raridon, This is what's given: In a rectangular coordinate system, a positive point charge q ... A: #2, if it's E at the origin, then that's 0. for your new problem, you need to put in the distance to ... | |
| Light | 7/5/2009 |
| Q: Can you tell me what kind of light can't go through the water. For example, umbrellas can block UV. ... A: You're not talking about visible light since UV is outside the visible range. Both are just part of ... | |
| physics | 7/4/2009 |
| Q: The displacement of an oscillating mass is given by x(t) = 20 cos( 5 t ). 1)What is the initial ... A: Do you understand that velocity is the rate of change of displacement and acceleration is the rate ... | |
| Electric Field Mapping Question! | 7/2/2009 |
| Q: Raridon, I have a question regarding a Physics lab on Electric Field Mapping! The question is as ... A: I presume you're sketching out electric field lines between parallel plates. In the central region ... | |
| capicetance | 6/30/2009 |
| Q: we know that c= q/v if q=1c and v=1volt then c=1f this is very big ... A: Obviously because 1C is a very large charge. If a 1 Farad capacitor had plates separated by 1mm, ... | |
| need help. | 6/29/2009 |
| Q: 1)WHEN A BUCKET FULL OF WATER IS RAPIDLY WHIRLED IN A VERTICAL CIRCULAR PATH WATER DOESN'T FALL EVEN ... A: 1) That's because there's a centripetal force due to the water moving in a circular path that ... | |
| electricity | 6/28/2009 |
| Q: In electricity practicals when you turn up the voltage the current will increase. But when ... A: Sure, if you have a constant resistance then increasing the voltage increases the current, V = IR. ... | |
| physics | 6/27/2009 |
| Q: A 1100-kg rocket has a net propulsion force of 70 kN (kiloNewtons). Over a short time period, it ... A: 1. 35m/s to 60m/s = 25m/s change, convert to mph 2. Impulse = Ft = 70000(0.393) 3. v = v0+at so 60 = ... | |
| physics | 6/21/2009 |
| Q: Block 1 (m1=1.5 kg) and block 2 (m2=1 kg) are on the surface of a table as shown in the figure. The ... A: The normal force on m1 = 1.5(10)-5 = 10N The normal force on m2 = 1(10) = 10N Frictional force on ... | |
| should we spend time in the sun ?? | 6/17/2009 |
| Q: well im doing a science exam in school at the moment and im woundering weather you can help me. im ... A: A short time in the sun wearing sunscreen will help you produce Vitamin D. Spending extensive time ... | |
| physics | 6/17/2009 |
| Q: Forces F1 and F2 act on a mass m = 0.79 kg, as shown in the diagram below. The magnitudes of the ... A: 1) F1x = 3cos(79) = 0.57N, F1y = 3sin(79) = 2.94N 2) F2x = 3.6cos(15) = 3.48N, F2y = 3.6sin(15) = ... | |
| physics | 6/17/2009 |
| Q: Forces F1 and F2 act on a mass m = 0.89 kg, as shown in the diagram below. The magnitudes of the ... A: 1) F1x = 1.9cos(51) = 1.20N, F1y = 1.9sin(51) = 1.48N 2) F2x = 3.7cos(26) = 3.33N, F2y = 3.7sin(26) ... | |
| physics | 6/16/2009 |
| Q: A cannonball is fired from a gun with a muzzle velocity of 80 m/s at an angle of 65 degrees above ... A: The vertical component of the velocity would be 80sin(65) = 72.5m/s 1) v = gt so 72.5 = 9.8t and t = ... | |
| About gravitational potential energy | 6/13/2009 |
| Q: I have a question regarding the formula g=GM/r^2: In my lecture notes, it says "For a spherical ... A: As you probably know, every bit of mass attracts every other bit of mass. The equation is F = ... | |
| Earth's Magnetic Field | 6/1/2009 |
| Q: Have heard two things on the Earth's magnetice field that it is reversing and/or will decline to ... A: The Earth has been going for about 4.5 billion years which is also approximately the half-life of ... | |
| Electrical Potential | 5/31/2009 |
| Q: Consider three identical metal spheres, A, B, and C. Sphere A carries a charge of -2.0 uC; sphere B ... A: After A and B are touched and then separated they will each have a charge of -4 uC. After B and C ... | |
| Emission And emission Spectra | 5/31/2009 |
| Q: Sir,,i am a new to atomic physics and have many queries in my mind.......i was recently studying ... A: 1) Yes, the substance has to be vaporized to produce a line spectra. Consider neon signs. A ... | |
| gravitational pull | 5/31/2009 |
| Q: i was just wondering about gravitational pull. Is it true that the sun pulls all planets in to their ... A: The planets stay in their orbits around the sun because of balanced forces. The force of gravity ... | |
| Electric field | 5/31/2009 |
| Q: What are the differences between electric and magnetic fields?Thanks A: electric fields surround electric charges. electric field lines start at a positive charge and end ... | |
| physics | 5/28/2009 |
| Q: After repeated pleas, mention of liability issues and possible criminal prosecution for negligence, ... A: Regardless of the mass, any body falling experiences 1 g. It's not the falling that hurts you, it's ... | |
| Physics | 5/27/2009 |
| Q: A common saying goes, "it's not the fall that hurts you; it's the sudden stop" Translate this into ... A: That's Newton's second law, F = ma. The attraction between your body and the Earth is given by F = ... | |
| in nuclear reactions | 5/27/2009 |
| Q: Richard I'm somehow confused about liberated energy and total energy, I'd like to know the ... A: I assume you're talking about radioactive atoms. They are unstable and want to go to a lower energy ... | |
| Energy | 5/27/2009 |
| Q: I am a business major from East Carolina University and have limited experience with physics. Still ... A: Energy is created and destroyed all the time in nuclear reactions. We get our energy from the sun ... | |
| fluid dynamics | 5/26/2009 |
| Q: I am in high school 11th grade I never heard of fluid dynamics before i read about it in a web so i ... A: Fluid dynamics obviously deals with fluids moving. That can be water, air , or another fluid. I ... | |
| Liberated energy nuclear reactions | 5/23/2009 |
| Q: Richard where does liberated energy go to? and why it's liberated? and why do we have (M before- M ... A: In certain atomic reactions, such as take place in our sun, the mass of the product is less than the ... | |
| nuclear physics | 5/18/2009 |
| Q: sir I want to ask that what are the reasons that half life of a radioactive substance is smaller ... A: The half-life is the time for one half of a given number of radioactive atoms to decay to a lower ... | |
| Magnetism/Induction | 5/17/2009 |
| Q: Could you please clearly (and simply!) explain to me how an AC motor works? I am finding it ... A: It's sort of like keeping the rabbit in front of the dogs at the race track. The armature rotates ... | |
| some problems involving rotational motion | 5/14/2009 |
| Q: I got very confused at the physic lesson today, here are some problems I hope you can help me with. ... A: 10 Since it's not skidding you have to use the static friction which gives you 26.5m/s 2) T+mg = ... | |
| Work and Energy | 5/8/2009 |
| Q: A ball on a roller coaster of mass 0.01 kg with zero non-coservative forces seems to conserve its ... A: It looks like the first two sets fall within experimental error although I doubt that your accuracy ... | |
| levers? | 5/7/2009 |
| Q: I am having an argument with a puzzle publisher....please look at this picture. ... A: the editor is correct. you're dealing with moments, the product of force times distance which can ... | |
| production of electricity | 5/7/2009 |
| Q: how does a generator produce electricity how does photovoltaic cells produce electricity what are ... A: It would be better for you to go to www.wikipedia.com and put in "electrical generation" and ... | |
| Blacklights | 5/5/2009 |
| Q: Do you happen to know if anyone sells a very bright blacklight? Unlike those $50 Spencer's gifts ... A: By definition, a blacklight is not going to light up a room since ultraviolet is not visible light ... | |
| mass | 5/4/2009 |
| Q: i wanna ask how we can calculate mass of objects in space which no gravity exists!!? would u please ... A: mass has nothing to do with gravity. mass is a product of the volume of an object and its density. ... | |
| why should we spend time in the sun | 4/27/2009 |
| Q: what happens we when spend to much time in the sun and what does effects does it have on the earth ... A: You don't get as much sun there as we do in the US. While some exposure to the sun may be ... | |
| energy | 4/24/2009 |
| Q: Your help is very much appreciated. 1- A novice skier, starting from rest, slides down a ... A: 1- Since it's frictionless, you only have to consider the height. mgh = (1/2)mv^2 so v = 49.5m/s 2- ... | |
| Light Interference | 4/14/2009 |
| Q: Respected Sir, Do constructive and destructive light interference take place simultaneously? Is ... A: Light consists of waves. Waves have maxima and minima. If the maxima of two different waves occur ... | |
| Magnetic North, the amount of Iron | 4/6/2009 |
| Q: I am doing a report and had a question in my mind about the amount of iron required to be removed ... A: You can talk about a large usage of steel, but not infinite. If you removed all the iron from below ... | |
| friction | 4/6/2009 |
| Q: A 182 g block is launched by compressing a spring of constant k=200 N/m a distance of 15 cm. The ... A: The energy stored in the spring is (1/2)kx^2 = 2.25J The frictional force = 0.27(.182)(9.8) = 0.482N ... | |
| physics | 4/3/2009 |
| Q: Two identical pucks are on an air table. Puck A has an initial velocity of 2.3 m/s in the positive ... A: If two identical pucks collide elastically, the angle between them after the collision is 90 degrees ... | |
| physics | 4/3/2009 |
| Q: i have a problem i need help with. A 20 lb ladder that is 10 feet long leans against a smooth ... A: The ladder extends 8 feet up the wall and the base is 6 feet from the wall. If you take the moments ... | |
| Electricity | 4/2/2009 |
| Q: Respected Sir, I am student of class 11, Which is greater drift velocity attained by an electron or ... A: Thermal velocity is probably greater but that's random in all directions. Drift velocity is the ... | |
| physics(electricity) | 4/2/2009 |
| Q: please tell me the difference between resistance and resistivity in simple language.plz elaborate ... A: resistivity is a property of a material, just like density. You will find tables of resistivity ... | |
| magnetism | 3/28/2009 |
| Q: I'm a fifth grader doing a report on magnets.Some of my questions are... What's inside a magnet that ... A: Most magnets are made of iron, like what you find in a nail. They also use cobalt and nickel. It's ... | |
| moment of inertia | 3/26/2009 |
| Q: what is the moment of inertia ? A: inertia is a measure of how hard it is to move something. If you want to move something in a ... | |
| Physics: Torque Question | 3/26/2009 |
| Q: To Richard, Thank you so much for taking the time to read over my question regarding torque. This ... A: A lever is a simple machine. The mechanical advantage is the ratio of the long segment of the board ... | |
| Physics | 3/23/2009 |
| Q: I was just wondering if you could help me get started on this5. An electron is travelling in the ... A: The time for the electron to reach the plate is 3x10^-3/4x10^4 = 7.5x10^-8s. The acceleration to ... | |
| physics | 3/22/2009 |
| Q: Out of 8 coins you have with you, one is heavier while the remaining 7 coins have equal weights. By ... A: Put 3 coins on each side of the scale. If they weigh the same then the heavier coin is one of the ... | |
| electric field intensity | 3/20/2009 |
| Q: sir the electric field intentsity E of an infinite plane charged sheet is (charge density)/2 * ... A: E = kq/r^2 You have to sum this up over the entire sheet. For an infinite sheet you have a point in ... | |
| ELECTRICAL | 3/19/2009 |
| Q: you are observing the effect of a single ponit charge with a magnitude of +4.3( looks like ... A: I presume you mean 4.3uC where the u has a little tail on it. That's the symbol for "micro" or ... | |
| Physics Question | 3/18/2009 |
| Q: Raridon I have a question that I can’t find its answer. The question is: A person pulls a box on ... A: Your English is fine. Much better than my Iranian. I'm going to use u since I can't type mu, and ... | |
| Draging an object | 3/16/2009 |
| Q: I would like to know if you can guide me to find all the forms known to drag an object. If magnetism ... A: Certainly you can drag an object using a magnet if the object contains iron, cobalt, nickel or a few ... | |
| Physics | 3/15/2009 |
| Q: I just need some explanation, please? Determine the electric field at the origin o in Fig. Due to ... A: E = kq/r^2 = kQ/l^2 (a)E(A) is E straight down E(B) is 60 degrees west of south E(B) west is ... | |
| help plz | 3/13/2009 |
| Q: Q1. A projectile is launched at an upward angle of 30˚ to the horizontal with a speed of 30m/s. ... A: Q5. vcosA = 3/1.3 = 2.308m/s 0 = 5+[vsinA]t -(1/2)gt^2 so vsinA = 2.524m/s (a) so v = 3.42m/s at an ... | |
| help plz | 3/13/2009 |
| Q: Q1. A projectile is launched at an upward angle of 30˚ to the horizontal with a speed of 30m/s. ... A: Q1. The horizontal component of the velocity is constant throughout the flight, 30cos(30). Q2. ... | |
| Physics: Momentum? Help Please!!!! | 3/12/2009 |
| Q: To Richard, Thank you so much for taking the time to read over my question regarding momentum. This ... A: A. the car since it's smaller B. Probably not fair to ask me this since I taught physics and have ... | |
| physics | 3/10/2009 |
| Q: A 2.0 kg ball is thrown vertically from ground level into the air with an initial velocity of 10.0 ... A: V = V0 -gt so 3 = 10 -9.8t and t = 0.714s H = v0t -(1/2)gt^2 = 10(0.714)-4.9(0.714)^2 = 4.64m To ... | |
| Physics | 3/4/2009 |
| Q: 1. (a) A 1.23 kg ball is attached to a ceiling by a 1.92 m long string. The height of the room is ... A: 1(a) -23.1J (b) 44.4J (c) 0J 2. E = (1/2)kx^2 = 0.032J 3. F = mv/t = 337N 4. mv = Ft = 134kg-m/s ... | |
| motion | 3/3/2009 |
| Q: i've several Qs can u help me plz!! Q1. A horse canters away from its trainer in a straight line, ... A: Q1 (a) speed = distance/time = 174/18.8 = 9.26m/s (b) ave. vel. = 58/18.8 = 3.09m/s Q2 v = v0+at so ... | |
| Physics | 3/2/2009 |
| Q: A model rocket is fired vertically from rest. It has a net acceleration of 15.5 m/s2. After 2.0 s, ... A: v = at = 15.5(2) = 31m/s S = (1/2)at^2 = (1/2)(15.5)2^2 = 31m so after 2s, the rocket is 31m high ... | |
| magnetism and gravity | 3/2/2009 |
| Q: i was wondering based on a few small scale experiments of my own if magnetism is actually a stronger ... A: First of all, you don't get infinite energy as mass increases. It takes energy to get mass to go ... | |
| Physics | 2/27/2009 |
| Q: How do I differentiate among these terms when answering questions on friction, normal force, F=ma, ... A: Friction occurs between any two moving bodies. The normal force is the force perpendicular to the ... | |
| friction | 2/27/2009 |
| Q: Can you explain friction with the real time scenarios and with unfamiliar examples and also suggest ... A: You can put "friction" into Google or look it up in Wikipedia. There is friction between everything ... | |
| friction physics | 2/26/2009 |
| Q: an object with a mass of 10kg slids upwards on a slippery vertical wall. a force of 60 N acts at an ... A: I taught physics several years and I know that the answers in the book are not always correct. In ... | |
| Physics (Friction) | 2/25/2009 |
| Q: Book: physics Principles and problems 17. A girl exerts a 36 N horizontal force as she pulls a 52 N ... A: The symbol for coefficient of friction is the Greek letter mu. I'm going to use u. 17. u = 36/52 = ... | |
| physics | 2/18/2009 |
| Q: a person throws a ball up at 13 m/s. (neglect air friction). what is the acceleration at the highest ... A: The acceleration is constant throughout the flight, namely, g. The speed at the highest point is ... | |
| Height from a shadow | 2/15/2009 |
| Q: Presumably at some point the shadow of an object will be the same length as the height of the ... A: It's not easy to determine the angle of the sun. The easiest way to measure the height of a tree is ... | |
| Direction of the acceleration of a charge | 2/12/2009 |
| Q: I have a question about the behavior of charges in an electric field. I would like to know how the ... A: It's really both since the field at a given point is a function of the magnitude of the charge and ... | |
| bernoulli | 2/7/2009 |
| Q: In the steady flow, what is the factor that decreased the pressure and increased the velocity when ... A: There's no factor. It's just the fact that, if the fluid is incompressible, like water, then the ... | |
| Electric Circuits | 2/4/2009 |
| Q: I am somewhat confused by the Formula for Power- P=V*I and Ohm's law which says V=I*R. In the first ... A: Ordinarily, the voltage is fixed. In the US standard household voltage is 110-115 volts except for ... | |
| nuclear fusion | 2/3/2009 |
| Q: i want to know what exactly is the hindrance in building a nuclear fusion reactor. I mean , if the ... A: We get our energy from the sun because of fusion reactions taking place in the interior of the sun. ... | |
| Oscillation | 1/28/2009 |
| Q: Respected sir I am Mukul chakravarty of class 11 What is the difference between simple harmonic ... A: no, you could have a square wave that is harmonic and a constant amplitude. It has to be a sine ... | |
| Oscillation | 1/26/2009 |
| Q: Respected sir I am Mukul chakravarty of class 11 What is the difference between simple harmonic ... A: Harmonic motion simply means that the motion goes back and forth from some midpoint. Simple ... | |
| the speed of electrons | 1/22/2009 |
| Q: Do electrons in different atoms orbit the nucleus at different velocities? Do electrons go faster ... A: Yes,they orbit at different velocities since the velocity is a function of the distance of the ... | |
| Waves | 1/20/2009 |
| Q: Give an example of transverse wave and longitudinal wave in solids. A: In a transverse wave the material moves back and forth perpendicular to the direction of wave. That ... | |
| magnetic fields and waves | 1/16/2009 |
| Q: I'm not exactly sure how to word this. Can a large enough magnetic wave/field more or less ... A: Magnetic fields don't build up a physical pressure. The strength of electromagetic fields depends ... | |
| magnetically generated electricity | 1/9/2009 |
| Q: what are the pros and cons of using magnetically generated electricity? ANSWER: It's easy to do. I ... A: You can generate electricity from falling water, solar, windmills, geothermal, nuclear, and burning ... | |
| A lot of petty questions | 12/22/2008 |
| Q: I would very much appreciate your help in clearing my doubts.. 1. Energy is defined as the ability ... A: 1. Energy is only conserved under special conditions. In elastic collisions between two bodies, ... | |
| electricity | 12/17/2008 |
| Q: 2 bulbs in series of 60w and 100w of 220v .If the voltage in increased to 440v . Which bulb will ... A: If the bulbs are rated for 220v, then the resistances of the bulbs are 484 ohms and 807 ohms. If ... | |
| Coulomb's Law | 12/14/2008 |
| Q: I'm having alot of trouble understanding the basics of Coulomb's law. For one thing I can't get my ... A: Force on +70 = (9x10^9)(70x10^-6)(48x10^-6)/(0.35)^2 -(9x10^9)(70x10^-6)(80x10^-6)/(0.70)^2 (net ... | |
| dispersion of light | 12/11/2008 |
| Q: . I want to ask you that as we know after rain rainbow is formed when light passes through the ... A: It takes very special conditions for a rainbow to form. First of all, the weather has to clear ... | |
| Conservation of Mechanical Energy | 12/8/2008 |
| Q: What exactly is meant by the Conservation of Mechanical Energy and what are a few examples that show ... A: When you have an interaction between two bodies, Conservation of ME simply means that the ME before ... | |
| Why do many physicists insist that gravitation is actually a force? | 12/6/2008 |
| Q: What I don't understand is: If gravitation really is an actual force, then why doesn't it work in ... A: There's no question that Newton's Law of universal gravitation holds, and can be measured. It is ... | |
| About Nuclear physics | 12/2/2008 |
| Q: The radioisotope U-232 with 92 protons emits alpha particles with an energy of 5.30 MeV and has a ... A: (a) I get 2.97x10^-10s^-1 (b) I get 3.87x10^14 Bq, 1 Bq is 1 distigration/second (c) I forgot a ... | |
| Calculus in physics | 12/2/2008 |
| Q: The following is an example problem about using calculus in physics. I have learned calculus, but I ... A: I sent this problem to a friend and I have not yet heard back from him. My friend, who has a PhD in ... | |
| kinetic energy.. | 12/2/2008 |
| Q: i an new and i need help with two questions. 1) In billiards(pool), when the cue ball hits another ... A: 1) That only happens when the cue ball hits the other ball head on. The equation for conservation ... | |
| Radioactivity | 12/1/2008 |
| Q: A space probe to one of the outer planets is to be powered by a radioactive source containing 2kg of ... A: You should have recognized that I used 6x10^23 for Avogadro's number instead of 6.022. Using that ... | |
| Radioactive activity | 12/1/2008 |
| Q: A patient is to be given an injection of iodine-131 in an investigation of her blood volume.2 ... A: Half-life means that the activity drops by half in that period of time. If the half-life is 8 days, ... | |
| Half-life | 11/30/2008 |
| Q: What is the formula uses to calculate a) the effective half-life in body of the patient, b) the ... A: I don't know what you mean by "effective" half-life. The "biological" half-life relates to the time ... | |
| velocity | 11/17/2008 |
| Q: I've been absent from school for a while cause we moved and when i got to my new school the science ... A: The standard equation for mechanics is v = at where v is velocity, a is acceleration, and t is time. ... | |
| electricity | 11/17/2008 |
| Q: I am a bit confused about the relation b/w power, voltage and current as we know ... A: You can only transmit so much power and P =VI so for the same power if you increase the voltage you ... | |
| HELP! | 11/16/2008 |
| Q: I'm doing a plan& design lab to investigate how the terminal velocity of a "toy" parachute depends ... A: Somehow you have to determine the velocity which is the time to fall a certain distance. The only ... | |
| HELP! | 11/15/2008 |
| Q: I'm doing a plan& design lab to investigate how the terminal velocity of a "toy" parachute depends ... A: That would not be easy to do with simple equipment. First of all you would have to determine how ... | |
| magnetism | 11/12/2008 |
| Q: i have just studied electromagnetism(X standard), but i exactly do not know why certain (or rather ... A: Magnetism is due to magnetic domains that exist in certain metals and alloys. There are some ... | |
| to ask a question | 11/10/2008 |
| Q: when we say about electron they are bound to the nucleus but when we discuss about solid metal then ... A: If you're talking about a single atom, then, yes, the electrons circle the positive nucleus because ... | |
| Physics - Energy/Momentum | 11/4/2008 |
| Q: A 2kg ball travelling 4 m/s [E] collided with a 4kg ball travelling 5 m/s [W] in an elastic ... A: Mom. before collision = mom. after collision so (2)(4) +(4)(-5) = 2Va +4Vb Rel. velocity before ... | |
| psyics | 10/21/2008 |
| Q: What force would you have to exert on a 326-N trunk up a 21.0° inclined plane so that it would slide ... A: The component of the weight of the trunk down the plane is 326sin(21) = 116.83N The force of ... | |
| Electric current on electricity | 10/18/2008 |
| Q: Explain why the headlights of a car go dim when the starter motor is used. Bless you ANSWER: A car ... A: When we buy car batteries, at least in the US, they are rated for so many months, like 60. They ... | |
| Electric current on electricity | 10/18/2008 |
| Q: Explain why the headlights of a car go dim when the starter motor is used. Bless you ANSWER: A car ... A: Headlights have a certain resistance, R, and the power dissipated in them is I^2R. When the current ... | |
| Calculation Help | 10/17/2008 |
| Q: I have been asked a question which is outside my knowledge, I dont know if you can assist... There ... A: The only dimension you need is 2.4m tall. The distance from the wall to the base of the pack is ... | |
| Parameters of EM waves | 10/6/2008 |
| Q: I know that the wave length of EM waves has to do a lot with determining the type or "quality" of ... A: I told you the speed was the same for all frequencies. The product of the frequency and the ... | |
| Parameters of EM waves | 10/5/2008 |
| Q: I know that the wave length of EM waves has to do a lot with determining the type or "quality" of ... A: The EM spectrum consists of gamma rays, x-rays, ultraviolet, visible light, infrared, short radio ... | |
| Relative velocity | 10/3/2008 |
| Q: A boy standing in a lift that is moving (a) upwards and (b) downwards at a constant speed of 5 m/s ... A: Sure, initially, the ball was moving up at the rate of 44m/s relative to the boy when the boy was ... | |
| Relative velocity | 9/30/2008 |
| Q: A boy standing in a lift that is moving (a) upwards and (b) downwards at a constant speed of 5 m/s ... A: Since the boy is moving down at 5m/s you have -5t=44t-4.9t^2 and t = 10s Why are you giving me a ... | |
| "forces & equilibrium" @ mechanics | 9/28/2008 |
| Q: Can you please give explaination to the solutions bit by bit in brief ? Because i actually cant work ... A: If the angle c were 90 degrees or less, the resultant would have a minimum value of 14.14. ... | |
| Questions on E&M continued | 9/23/2008 |
| Q: 5) (Circuits) How do I determine where the loop crosses a resistor? In the direction of current or ... A: (5) resistors are circuit elements that can have currents passing through them. The currents can ... | |
| Questions on E&M | 9/23/2008 |
| Q: please help with a few problems on electric and magnetic field. 1) When 2 objects are in contact, 1 ... A: (1) I don't know of a method (2) r is the distance between the charge and the point where E is being ... | |
| gravitaion | 9/21/2008 |
| Q: why is the gravitational potential enrergy of a body on mass m the surface of earth in the ... A: That's not an equation for PE. The force of attraction between two masses is given by F = GMm/R^2 ... | |
| big bang | 9/17/2008 |
| Q: I'm a little confused about big bang theory. How was all the mass of the Universe created at this ... A: Scientists think that protons and neutrons may be made up of hadrons, quarks, and other strange ... | |
| Newton's Laws | 9/17/2008 |
| Q: I am in a college algebra-based physics course, and I am having trouble with my homework problems. ... A: The vertical component of the initial velocity is 4.7sin(40) = 3.20m/s. So the time for it to get ... | |
| physics question | 9/16/2008 |
| Q: A skier is gliding along at 3.0 m/s on horizontal, frictionless snow. He suddenly starts down a 16° ... A: the height of the castle wall is (1/2)gt^2 = 19.6m the cannonball has an initial velocity of 20m/s ... | |
| making mass from energy | 9/15/2008 |
| Q: In nuclear physics we often hear about energy coming from mass e.g.Nuclear bombs and nuclear power. ... A: Atoms are not made of packets of energy. They're made of protons, neutrons and electrons. Mass and ... | |
| radius of curvature | 9/14/2008 |
| Q: sir can you explain me what is meant by radius of curvature of any curved surface? kats A: If you tied a string to a pencil, held the other end of the string, and rotated the pencil along a ... | |
| gravitation | 9/13/2008 |
| Q: sir few questions on gravitation 1) the gravitational force is inversly proportional to the ditance ... A: 1) yes 2) It does move toward the ball but not enough for you to see 3) Because the body is ... | |
| electicity,electrostatics | 9/12/2008 |
| Q: 1)electron moves from i) + plate to - plate ii)- plate to + plate. wat happpens to its P.E. 2)what ... A: 1) an electron is not going to move from + to - by itself. you'd have to add energy to it. going ... | |
| physics | 9/10/2008 |
| Q: what is the difference between current and voltage? which one has the greatest power?current or ... A: Voltage is the potential difference between two points in a circuit. I'm sure you're familiar with ... | |
| friction | 9/9/2008 |
| Q: sir we were doing this practical in physics of finding the coeeficient of static friction using an ... A: 3) no 2) ideally, your readings should be the same for different weights. However, in this case the ... | |
| circular motion | 8/4/2008 |
| Q: sir i want to ask when a stone tied to one end of a string and whirled around in the horizontal ... A: 1. because gravity acts straight down, perpendicular to the direction of motion. 2. it does come ... | |
| Electrostatics | 7/27/2008 |
| Q: I have a question for you. When I study the electrostatics,there is two concepts that I ... A: First of all, a few electric field lines are just sketched in for convenience. There are an ... | |
| Physical Science | 7/19/2008 |
| Q: Most of the radioactivity we personally encounter come from what? A: We have radioactive C-14 and K-40 in our bodies naturally. There are small amounts of uranium in ... | |
| optics | 6/26/2008 |
| Q: my question is that why white light has less energy than voilet light usually given answer is that ... A: You realize, of course, that white light is not just 7 wavelengths, but an infinite number of ... | |
| Mechanics_force | 6/26/2008 |
| Q: Richard, well how force transports? does it seperate when it reaches two parallel ways after it was ... A: Something has to produce a force. Your body produces a force on the ground which we call "weight". ... | |
| energy transports?! | 6/16/2008 |
| Q: Richard, well, when we hit a table (example) by our hand, energy created by us is transported from ... A: That's transfer of momentum. The first ball has momentum of mv. Since each ball has the same mass, ... | |
| PHYSICS: RC Circuits | 6/15/2008 |
| Q: what are the equations to find the voltage and capacitance of a RC Circuit in series? The circuit ... A: The capacitance will be whatever the value of the capacitor is. If you put it in series with a ... | |
| magnetic field | 6/10/2008 |
| Q: are electrons able to transport between the two poles (north, south)?? thanks for listening ANSWER: ... A: The result is never neutral. No matter how close the poles are to each other there's still a ... | |
| optics | 6/5/2008 |
| Q: sir i wanted to ask two questions related to refraction and apparent depth 1) When light travelling ... A: 1)Glass is really a supercooled liquid. If the index of refraction is the same then it's as if you ... | |
| in mechanics | 6/4/2008 |
| Q: what's the difference between force and energy?? thanks for listening. A: Force is a vector quantity and when it is applied to a mass it causes an acceleration. F = ma ... | |
| speed of sound lab | 6/3/2008 |
| Q: I had some questions about a speed of sound lab. The lab is performed by using a few different ... A: 1. In the first method you avoid using the distance to the first resonance so it should be more ... | |
| Physics(Electrostatics) | 5/30/2008 |
| Q: A charged capacitor has a dielectric slab placed inside the plates. The slab is removed & then ... A: If C is the capacitance of the capacitor without the dielectric, then the energy stored in the ... | |
| electrostatics | 5/26/2008 |
| Q: theThree identically charged particles are placed on the tips of an equalateral triangle. Draw the ... A: Since the force on each particle will be the same, it's pointless to indicate relative magnitude. ... | |
| Electromagnets | 5/20/2008 |
| Q: I am looking to build a pretty strong electromagnet. A: how do I go about it, B: how strong can an ... A: If you had ever seen one pick up a car you would know that they are enormous, probably several ... | |
| physics | 5/18/2008 |
| Q: what is the relation between, velocity,accelration & displacement a7 what is rms values. i tying to ... A: velocity is the rate of change of displacement with time. d = vt acceleration is the rate of change ... | |
| Human powered flight | 5/9/2008 |
| Q: I saw somewhere, that a human flew a pedal powered helicopter, (it was only about 1 or 2 feet high, ... A: There's no way a helicopter 1-2 feet high could lift a human. For a fan with a 10 ft. diameter, ... | |
| Polarization | 5/8/2008 |
| Q: I would like to know what Polarization is and how it works. A: light is electromagnetic radiation and vibrates back and forth in all directions perpendicular to ... | |
| Characteristic X-ray spectrum | 5/5/2008 |
| Q: Why is the intensity of the characteristic wavelengths of a X-ray emission spectrum much higher than ... A: An x-ray spectrum has a certain amount of background radiation called Bremsstrahlung. Superimposed ... | |
| I think I found the error | 5/5/2008 |
| Q: I believe he transposed two numbers while copying the equation for determining the speed: His ... A: What do you mean "right" answer? Putting in 0.110 means you're assuming the plate was deformed 11cm ... | |
| The metre | 5/3/2008 |
| Q: I understand that the metre is defined as the length of the path travelled by light in a vacuum ... A: The meter was originally defined as the difference between 2 marks on a Pt-Ir bar maintained at the ... | |
| Physics Q's | 4/27/2008 |
| Q: with? 1.) Give Neils Bohr's explanation for the existence of Hydrogen spectral lines? 2.) The speed ... A: 1) you can find that in a physics text book or the internet 2) nothing will happen 3) different ... | |
| Electricity and Magnetism | 4/23/2008 |
| Q: This question has the same information but a different question. A proton having an initial ... A: The path of the proton is in a plane. Does your expression "ex" mean that the proton is initially ... | |
| Mechanical Advantage of a pulley sestem | 4/21/2008 |
| Q: I am a professional Firefighter for the city of Rochester, NY. I have a question involving ... A: It's a simple pulley system. There are two clues as to why it's 2:1. First of all, the tension in ... | |
| science- physics | 4/21/2008 |
| Q: could you please answer these questions beacsue im really stuck in my school work! Should we spend ... A: Since I have had several skin cancers removed due to long sun exposures when I was young I do not ... | |
| polution | 4/12/2008 |
| Q: As recently as 100 years ago a major problem in cities was pollution...IE fecal matter emitted by ... A: Pure electric cars, using batteries, do not emit any more gases than your electric toaster or razor. ... | |
| Physics | 4/2/2008 |
| Q: Q1=Circuit breaker has more advantage than fuse.Explain why? Q2=The filament of electric bulb is ... A: 1- don't have to pay to replace the fuse 2- it needs to have high resistance 5- resistance increases ... | |
| Forces from motion | 3/25/2008 |
| Q: I am not fully understanding motion diagrams. I know that their will always be gravity pulling an ... A: You will always draw the force of gravity acting straight down. Just draw the various forces, ... | |
| force | 3/25/2008 |
| Q: sir thank you first for replying mu previous questions on force sorry for bugging you but since ... A: 1) an object in water does either float or go to the bottom, nothing in between except for a ... | |
| Nuclear energy | 3/24/2008 |
| Q: Regarding the generation of power with the use of uranium: 1. The radioactive waste that is spent ... A: 1. yes 2. Pu-239 plus a neutron becomes Pu-240 which splits into two pieces like U-236, forming ... | |
| Nuclear energy | 3/24/2008 |
| Q: Regarding the generation of power with the use of uranium: 1. The radioactive waste that is spent ... A: Uranium in nature occurs in two forms, U235 and U238, with less than 1% U-235. They each have ... | |
| nuclear physics | 3/24/2008 |
| Q: sir, the argument given for the unstability of radioactive nuclei is that the ratio of number of ... A: There are nuclear forces holding the nucleus together. If the ratio of neutrons to protons is ... | |
| Ice Crystals | 3/24/2008 |
| Q: This is mywhy is in the middle of ice, white ? (have you noticed ?) I guess the reason must be ... A: I have answered over 4000 questions in the past 3-4 years and seldom do I know where they come from. ... | |
| force and gravity | 3/23/2008 |
| Q: sir few questions on force and force of gravity 1) Why does inertia of an object depend on mass ... A: 1) Inertia is resistance to movement so that applies to objects just to get them moving from rest as ... | |
| colors | 3/21/2008 |
| Q: 1. What color of visible light has the longest wavelength? The shortest? 2. Why is red paint red? 3. ... A: 1. red longest, violet shortest 2. because it absorbs the other colors and reflects red 3. sure, ... | |
| Laser Projector | 3/18/2008 |
| Q: I was wondering if there is any such thing as a movie type projector that uses laser light, or if ... A: There are laser light shows but the problem of projecting a movie onto a cloud would be the fact ... | |
| Netwons law | 3/18/2008 |
| Q: Imagine a cannon that is free to roll on wheels. According to Newton's third law, the interaction ... A: It's a question of momentum. Before the cannon is fired, the momemtum of the system is zero. After ... | |
| Properties of Light | 3/15/2008 |
| Q: What does a changing magnetic field induce? What does a changing electric field induce? What ... A: 1. a changing electric current 2. a changing magnetic field 3. since electromagnetic waves range in ... | |
| acceleration | 3/10/2008 |
| Q: This seems a simple problem but no one can explain it in a language i understand. If 1 car ... A: Two standard equations of motion are v=at and v^2 = 2aS where a= acceleration, v=velocity, t=time ... | |
| a Vacuum Chamber Battery concept | 3/8/2008 |
| Q: I was thinking lately about vacuum chambers that slowly let compressed air back in through a linear ... A: Do you expect to get more energy out of the system letting air in that it took to suck the air out ... | |
| energy bonds | 3/6/2008 |
| Q: A 120 g block of ice at 0 degrees C is placed in an insulated thermos containing 420g of water at 22 ... A: If t is the final temperature, then 120(80) +120t = 420(22-t) which leads to a negative t, not ... | |
| transformers | 3/5/2008 |
| Q: when a step down transformer is used for stepping down a high voltage of some kilovolts to a few ... A: Any losses are a function of the way the transformer is made. Obviously, you're running current ... | |
| Projectiles | 3/5/2008 |
| Q: IS it possible to calculate the firing angle of a projectile if you are only given the x and y ... A: For the vertical distance you have y = y0+(vsinA)t -(1/2)gt^2 for the horizontal distance you have x ... | |
| standing wave | 3/3/2008 |
| Q: I don't know how to do thisA 40-cm-long tube has a 40-cm-long insert that can be pulled in and out. ... A: The standing waves occur when the length changes by half a wavelength so the wavelength is 28.4 cm ... | |
| phys | 3/1/2008 |
| Q: can you check these answers for me please? thank you VERY much. 1 a. gases are much less dense than ... A: 1. a, c, and d are correct. b. pressure is inversely proportional to volume (Boyle's Law) 2. 8000Pa ... | |
| Potential energy | 2/28/2008 |
| Q: Imagine that you are replacing a tire on your car on a steep hill in San Francisco, and somehow your ... A: The tire drops a vertical distance of 85sin(14) = 20.8m So mgh = (1/2)mv^2 which gives you 20.2m/s ... | |
| Light - Fading out | 2/25/2008 |
| Q: Sir, I am very new to physics, but of late, I have been trying to learn things by reading stuff ... A: Light is electromagnetic radiation, like x-rays, radio waves, microwaves, etc. Light from our sun ... | |
| Atomic Physics | 2/25/2008 |
| Q: Lately I had a question on Atomic physics regarding gamma rays. Beta and alpha rays cannot pass ... A: a) gamma rays are absorbed by everything, including Al and concrete. However, they are not stopped ... | |
| Downhill physics | 2/22/2008 |
| Q: A 70kg snowboarder is cruising straight down a hill at 20 mi/h. The slope of the hill is due south ... A: Gravity obviously acts straight down. The component of gravity down the 30 degree slope is ... | |
| weight | 2/22/2008 |
| Q: sir since i could not get any other experts free to ask this question i am asking this question to ... A: You could, but you wouldn't get an accurate reading. Spring balances are calibrated with ... | |
| Batteries | 2/19/2008 |
| Q: How exactly do batteries work, and could one make an effective battery using hot sauce as a strong ... A: Your father may be refering to a car battery. They have two electrodes, one is Pb and the other is ... | |
| jumping off a bridge | 2/19/2008 |
| Q: Prof. Raridon, Hi. My name is Stella Ramsey. I am in Mr. Swift's 2nd grade class at Lapham ... A: You must be pretty good swimmers. If you jump off head first you obviously don't want to hit the ... | |
| Batteries | 2/19/2008 |
| Q: How exactly do batteries work, and could one make an effective battery using hot sauce as a strong ... A: Chemical reactions take place inside a battery which convert chemical energy into electrical energy. ... | |
| phyical science | 2/17/2008 |
| Q: why does it take longer time for different liquids to evaporate ANSWER: One of the properties of ... A: No, the boiling point occurs when you heat a liquid up and it evaporates rapidly. For example, the ... | |
| The Conservation of Mechanical Energy | 2/17/2008 |
| Q: A 47.0 g golf ball is driven from the tee with an initial speed of 54.0 m/s and rises to a height of ... A: (a) v^2 = 2gH = 2(9.8)(25.2) so v = 22.2m/s That's the initial vertical velocity which means it ... | |
| physics | 2/11/2008 |
| Q: 1) can you give me the nuclear equations for the beta decays of Sr, C, Cs, and Np? 2) Uranium-238 ... A: 1. Sr-90 -> beta + Y-90, C-14 -> beta +N-14, Cs-137 -> beta +Ba137, Np-239 -> beta + Pu-239 2. ... | |
| High Magnetic Fields | 2/8/2008 |
| Q: I'm a 3rd year physics student at notts uni, uk. I have a pair presentation on high magnetic fields ... A: Why do we build bigger and bigger atom smashers? Because you can investigate more things. Same ... | |
| collision | 2/8/2008 |
| Q: During the filming of a certain movie scene, the director wants a small car (mass 750kg) traveling ... A: The momentum of the car is 750(35) and the momentum of the truck is 3200v. Afterwards, the momentum ... | |
| fission | 2/3/2008 |
| Q: sir 1) can you explain why Uranium 235 can not undergo fission with a fast moving neutron or why ... A: 1) In order for U-235 to undergo fission, it has to capture a neutron and become U-236. The neutron ... | |
| Another Physics problems: Pls help | 1/31/2008 |
| Q: 1.) A rock is dropped into a 60 meter deep well. Neglecting air resistance how long will it take the ... A: 1) S = (1/2)gt^2 = 4.9t^2, put in t = 1,2,3 and solve for S 2) v^2 = 2gS = 2(9.8)(2.5), solve for v. ... | |
| 8 questions... simple. | 1/31/2008 |
| Q: 1. When a solid (1) is heated, it breaks up into a gas and another solid (2). The solids and the gas ... A: Some of your questions are confusing 1. What do you mean by a "pure substance"? 2. If you start with ... | |
| what does watt mean | 1/25/2008 |
| Q: I have a space heater that I think is eating up my electricity. I calculated that it pulls 12.5 amps ... A: watt is a rate, joules/second, so if your heater is on for the whole 24 hours, that's 36 ... | |
| static electrcity | 1/16/2008 |
| Q: sir i hav few questions on static electricity 1) Why does a chit chat sound is heard when we rub our ... A: 1) any sound produced is mechanical 2) you don't have to comb your hair in the dark to produce a ... | |
| Electrostatics | 1/15/2008 |
| Q: A solid metal sphere of radius 5cm and a hollow metal sphere of radius 10cm, each have one coulomb ... A: For the solid metal sphere E = 9x10^9(1)/0.05^2 = 3.6x10^12 at the surface of the sphere. Just ... | |
| Hamster powered night light | 1/15/2008 |
| Q: I am doing a science project on making a hamster powered night light, and I am in 8th grade. We are ... A: I looked at the web site. That's a neat idea but I don't how you're going to be able to do it in a ... | |
| physics question | 1/14/2008 |
| Q: I recently purchased a motorcycle ramp that has a 500 lb static load limit and I would like to know ... A: Both a and F are vector quantities and since a is parallel to the ramp F is also. The tires ... | |
| water | 1/9/2008 |
| Q: If you hold a marble and a brick underwater (e.g., pool), which will hit the bottom faster, or both ... A: Yes, after dropping a short distance objects reach a terminal velocity which is given by ... | |
| electrons and protons | 1/9/2008 |
| Q: I was wondering what a negative charge really is. i understand that electrons carry a negative ... A: Electrons and protons are masses that happen to have opposite charges. That's just the way nature ... | |
| electrons and protons | 1/8/2008 |
| Q: I was wondering what a negative charge really is. i understand that electrons carry a negative ... A: Scientists know that atoms are electrically neutral. They know that protons and electrons have an ... | |
| electricity | 1/4/2008 |
| Q: sir i hav one doubt regarding a numerical in teh following circuit diagram we hav to find teh ... A: In this case the 20V battery is putting energy into the system and the 8V battery is being charged ... | |
| quick question | 1/4/2008 |
| Q: I cannot stop thanking you! Your help is so amazing! Just some final questions: You used v=gt ... A: Well, the time is the same whether you calculate for something dropping or something rising. ... | |
| please help! | 1/3/2008 |
| Q: I would greatly appreciate any help you may provide to me regarding the following question. I have ... A: Since the momentum in the x-direction is zero after the collision, 18(25) = 12vcos(60) where v is ... | |
| potential difference | 12/23/2007 |
| Q: I am learning about electric potential difference, and wonder if my understanding of it is correct. ... A: In order for 1C of positive charge to move from A to B, B would have to be negative relative to A, ... | |
| portable light | 12/20/2007 |
| Q: I need assistance with making a portable light for hunting. I have a 12 volt, 3M candlepower ... A: They don't seem to have a "physics" category or I would sign up for it. Does your light have a ... | |
| negative and positive charge | 12/16/2007 |
| Q: what exactly is a negative and positive charge. i have always been told negatives and positives like ... A: Atoms have a nucleus containing protons and neutrons with electrons circling around. Electrons have ... | |
| physics | 12/6/2007 |
| Q: A sphere of mass 2.8x10^-4 kg is suspended from a cord. A steady horizontal breeze pushes the sphere ... A: You know F, you know sin(37), you can find T I'm sorry. I assumed you were smart enough to ... | |
| physics | 12/1/2007 |
| Q: A uniform plank of length 4.1 m and weight 203 N rests horizontally on two supports, with 1.1 m of ... A: To the left of the right support is 3 m of plank which has a weight of 148.54N. To the right of the ... | |
| in need of a trebuchet expert | 11/28/2007 |
| Q: I am doing a project on trebuchets, specifically comparing the optimization of medieval trebuchets ... A: I talked to a friend of mine who knows a lot about trebuchets but doesn't have time to correspond ... | |
| physics | 11/25/2007 |
| Q: I know you don't answer homework questions but i need someone to tell me how to go about this ... A: You can write the exponents as 1.5x10^4, 2.3x10^11, etc. From Kepler's Law, T^2/r^3 is a constant ... | |
| Atomic physics | 11/6/2007 |
| Q: I just had one question. My professor hasn't been explaining this terribly well, and I was hoping ... A: Air is a mixture of N2 and O2. I presume you know about Avogadro's number, the number of molecules ... | |
| Physics | 10/28/2007 |
| Q: A battery of e.m.f 15V and internal resistance 2 ohm is connectedto 2 resistors of 4 ohm and ... A: (a) the current through each resistor is 15/12 = 1.25 amps Watts = I^2R = (1.25^2)(6) = 9.38 J/s = ... | |
| E=MC^2 with Hydrogen | 10/23/2007 |
| Q: I'm a little confused with E=MC^2 in Hydrogen. If you introduce an electrical field of 13.6 volts ... A: You can't propel a proton into a helium nucleus. The force of repulsion between positive charges ... | |
| flux | 10/12/2007 |
| Q: I am working on some practice problems in a book and came across one where i got stuck. Basically, ... A: Except for the base of the bulb, the light goes out in all directions. It's not enough to just know ... | |
| light | 10/11/2007 |
| Q: "Clear," light into it's three primary colors (red Yellow blue). My question is this: are the ... A: In a vacuum, or almost in air, the velocity of every wavelength of electromagnetic radiation, ... | |
| light | 10/11/2007 |
| Q: "Clear," light into it's three primary colors (red Yellow blue). My question is this: are the ... A: Visible light consists of electromagnetic energy with wavelengths between 400 and 750 nm. A prism ... | |
| question regarding general physics | 10/9/2007 |
| Q: (1) Two astronauts are in outer space connected with a rope in a state of complete weightlessness. ... A: (1) They are not "weightless". Their weight due to the pull of gravity is balanced by the ... | |
| Egg Drop project | 10/6/2007 |
| Q: what would i have to write in the introduction about a design of the egg drop experiment where the ... A: You want the socks and the bands to absorb the momentum when the box hits the ground so that the egg ... | |
| Physics Help! | 9/15/2007 |
| Q: Help would be great!! thank you :) #1 A bicycle travels 3.2 km due east in 0.10 h, then 3.2 km at ... A: #1 total distance east = 6.4 +3.2sin(15) = 7.23km total distance north = 3.2cos(15) = 3.09km ... | |
| physics question | 9/15/2007 |
| Q: I need help with this problem, I can't figure it out: A cannonball is catapulted toward a castle. ... A: The initial vertical velocity is 38sin(45) = 26.87m/s The horizontal velocity (constant throughout) ... | |
| Physics question | 9/14/2007 |
| Q: I have tried this problem a few times and every time I get the wrong numbers, could you please help ... A: The initial vertical velocity is 18.7sin(25) = 7.90m/s v^2 = 2gh so 7.9^2 = 2(9.8)h so h = 3.18. ... | |
| Question on Gravity | 9/12/2007 |
| Q: We often here people talk about "defying" gravitity and "suspending" gravity. Can these words be ... A: Any object that has mass is attracted to every other object that has mass. We define gravity as the ... | |
| Power Savers | 9/12/2007 |
| Q: As a student living with 6 others i have been looking at ways to cut down our energy use to save ... A: It probably just reduces the voltage from 115 to about 100 which means your 100 watt bulb would only ... | |
| dimension | 9/7/2007 |
| Q: . Is the dimensions are suggested only for length, time and mass? or for all other base quantities ... A: The basic standards for mass, length and time, generally called the MKS system, since the metric ... | |
| Physics | 9/4/2007 |
| Q: I am having trouble understanding what to do with the information given in the following equations: ... A: 1) H = (1/2)gt^2 = 4.9(1.5)^2 = 11.02m v^2 = 2gh = 2(9.8)(11.02) so v = 14.7m/s 2) The package will ... | |
| Velocity | 8/28/2007 |
| Q: Will different balls have different velocities when they strike the ground? A: How far are they falling? If it's only a short distance, a few hundred feet, then the answer is ... | |
| ballistic pendulum | 8/27/2007 |
| Q: Im a in a first year under graduate physics paper, i'm doing a projectile motion experiment with a ... A: I'm sure you're aware that the pendulum containing the projectile rises above its original position. ... | |
| Concrete | 8/26/2007 |
| Q: I am trying to determine what is the impact, per square foot, at ground level of a concrete object ... A: You have an impact area of 0.28 ft^2 so you can calculate the force per unit area. However, you can ... | |
| Potential Dividers | 8/26/2007 |
| Q: My question relates to the effect of current drawn at a point, say point b, between R1 and R2 in a ... A: I = 15/(10+x) and 10+x = 10+5R/(R+5) = (15R+50)/(R+5) so I = 15(R+5)/(15R+50) iR = 15-10I = 15 ... | |
| Friction force comparison | 8/23/2007 |
| Q: I have 2 clothes irons that are weighted the same. One unit slides down an incline at 13 degrees ... A: the coefficient of friction is the tangent of the angle so in one case that's tan(13) and the other ... | |
| electromagnetism | 8/23/2007 |
| Q: sir can you explain me why does a current carrying conductor has magnetic field around it. why does ... A: Do you understand why, if you drop something, it falls to the ground? It's just a property of ... | |
| Classical Mechanics | 8/22/2007 |
| Q: There are two pulleys with a rope to each one. How come that the tension in the rope and the angular ... A: As you said, the pulley with just the force is straight forward, with Tr = Ia where a is the angular ... | |
| presure | 8/21/2007 |
| Q: sir i want to ask few questions on water pressure 1) why does water seeks its own level? 2) In a ... A: 1) If it didn't it would violate the principle of conservation of energy. 2) The tanks would have to ... | |
| Potential Dividers | 8/20/2007 |
| Q: My question relates to the effect of current drawn at a point, say point b, between R1 and R2 in a ... A: Okay. Let R = your unknown resistance that will be parallel with the 5 ohm resistance. Then ... | |
| Potential Dividers | 8/17/2007 |
| Q: My question relates to the effect of current drawn at a point, say point b, between R1 and R2 in a ... A: Yes, it always helps to have the whole picture. (d) I = V/R so the only ways you can have ... | |
| Potential Dividers | 8/16/2007 |
| Q: My question relates to the effect of current drawn at a point, say point b, between R1 and R2 in a ... A: I gather that Vout is the voltage across R2. Since I = V/R, for zero current, R2 would have to be ... | |
| capacitors | 8/14/2007 |
| Q: what is edge effect in capactors??? A: The capacitance of a capacitor is proportional to the cross sectional area of the plates and the ... | |
| feeling acceleration | 8/2/2007 |
| Q: a human can feel acceleration, including rotational acceleration. when on a merry go round which ... A: 1000 mph is the velocity of an object at the equator as the Earth rotates. The angular acceleration ... | |
| electricity | 8/2/2007 |
| Q: now there are three wires coming to our home, live , neutral and earth. The live wire in india is at ... A: The neutral wire is connected to the ground which is defined as zero potential. The electricity is ... | |
| physics | 7/26/2007 |
| Q: a person standing on a weighing machine sits down with a jerk and the weighing machine shows a ... A: A weighing machine measures force. Your weight is the force due to gravity pulling your body toward ... | |
| water | 7/23/2007 |
| Q: Does hot water boil faster that room temp. and/or cold water? Why or why not? A: Water boils when the vapor pressure of the water equals the air pressure above it. Under standard ... | |
| electricity | 7/22/2007 |
| Q: why is the terminal voltage(when the current is drawn )of a cell less than the emf (when circuit is ... A: Simple, if E is the emf and V is the voltage, then V = E -ir, where r is the internal resistance ... | |
| potential | 7/18/2007 |
| Q: helo sir 1) I was reading the chapter on electric potential. Now the elctric potential in all books ... A: 1) Why do you think that positive charges can't move? It's true that electrons move through metals ... | |
| physics | 7/17/2007 |
| Q: when a projectile was fired from a gun, it had initial horizontal and vertical components of ... A: The horizontal velocity of the gun stays constant throughout its path, disregarding air friction. ... | |
| electircity | 7/15/2007 |
| Q: I have some questions based on electricity 1) why does a thin wire offer more resistance to current ... A: 1) It's not the surface area but the cross-sectional area that matters when calculating resistance ... | |
| physics-mechanics 2 questions | 7/15/2007 |
| Q: random questions out of the text i cannot seem to wrap my mind around. First year University Physics ... A: 1) let y = height above the window and t = time to drop to the top of the window. therefore, y = ... | |
| Atoms | 7/13/2007 |
| Q: I was wondering if there is any way to estimate the number of atoms that are in an object, such as ... A: Sure. the number of atoms in one gram-molecular-weight of a material is 6x10^23. That's 12 grams ... | |
| resonance | 7/12/2007 |
| Q: sorry sir again i have some doubt in resonance. since you amswered my previous questions very well, ... A: the frequency does not increase. that's a function of the tuning fork. suppose the wavelength is ... | |
| sound | 7/11/2007 |
| Q: sir i know that this may not really be related to your field, its related to resonance of sound, but ... A: 1) Sounds can be broken down into sine waves. If you add together two sine waves with the same ... | |
| magnets | 6/30/2007 |
| Q: I had a BBQ/picnic at my workplace a few weeks & the game I was in charge of was the duck pond. I ... A: I assume the magnets on the ducks were little disks. Did you take the other four off and see if ... | |
| Electricity | 6/24/2007 |
| Q: I would like to know how an electric bulb lights up as soon as the switch is pressed although the ... A: The same reason you get water out of a faucet as soon as you open it. The pipe is full of water and ... | |
| Light | 6/14/2007 |
| Q: I hope you are ok. I have always wondered if you have a hollow cube whose internal sides are made ... A: I'm fine. Right now I'm volunteering at the Science Museum in Oak Ridge, TN. Since there's no such ... | |
| Principle of conservation of energy | 6/10/2007 |
| Q: a) Explain the relevance of the principle of conservation of energy to: (1)a stone falling from rest ... A: 1) the stone loses potential energy which goes into kinetic energy. mgh = (1/2)mv^2 2) here, ... | |
| Physics-Magnetism | 6/9/2007 |
| Q: 1. What happens to the lines of force if unlike poles of two different magnets are placed close ... A: 1. You have to realize that there are an infinite number of lines of force surrounding any magnet. ... | |
| Projectile Motion | 6/8/2007 |
| Q: Why do any 2 angles that give the same range in projectile motion add upto 90 degrees? ANSWER: ... A: If the initial velocity of the projectile is v and the initial angle is A, then the range is given ... | |
| magnetic fields | 6/4/2007 |
| Q: i have 5 questions that i was wondering if you could possibly help me to answer, they are: 1) ... A: 1) B and H are related through magnetic permeability B = u0H where u0 is the permeability of free ... | |
| Momentum | 5/14/2007 |
| Q: A bullet with a mass of 45g is fired into a 8.3 kg block of wood resting on a floor against a ... A: The energy to compress the spring = (1/2)kx^2 = (1/2)(76)(0.28)^2 = 2.98J which is equal to the ... | |
| base and derived uinits | 5/14/2007 |
| Q: I think ampere(unit of current) is a derived unit but why it is considered as base unit? please tell ... A: Here's the definition from a physics book - If two very long parallel wires one meter apart carry ... | |
| Time Travel concept | 4/26/2007 |
| Q: I am curious about Time Travel. I have read and seen material on the topic. Most tend to sway to the ... A: Unfortunately, nothing that has mass, including us, can travel with the speed of light. Only very ... | |
| Physics Q's | 4/24/2007 |
| Q: let me know what you think. 1. hydrogen, with its one electron, can produce a line spectrum with ... A: 1. The electron can change from one level to another with the visible lines corresponding to an ... | |
| metal detectors | 4/22/2007 |
| Q: What is the significance of kiloherzs in metal detectors? They range from 10 to 17 Kz., and ... A: I can't comment on the significance of the frequency. It may have something to do with penetrating ... | |
| refraction | 4/22/2007 |
| Q: can u explain me why the constituent of white light (the seven colours)though having different ... A: First of all, there's not just seven colors, but an infinite number going from 400nm to 700nm. ... | |
| physics | 4/22/2007 |
| Q: what is potential and kinetic energy? Do all amusement park rides have this? A: Kinetic energy is energy of motion, KE = (1/2)mv^2 Potential energy is energy of position PE = mgh ... | |
| Physics | 4/18/2007 |
| Q: I was just wondering if you could answer this question for me:"The dam or dike is made thicker ... A: Just as divers find out, water pressure increases with depth. It should be obvious that water ... | |
| electrical conductivity | 4/17/2007 |
| Q: A dinner conversation revolved around the question of whether ice or water was a better electrical ... A: If they're both "pure", they're the same, both poor conductors. Water has be distilled to be free ... | |
| Physics | 4/15/2007 |
| Q: I once rode on an amusement park ride where riders stand against the inside of a cylinder, once the ... A: I was on one of those rides with my daughters at Six Flags over Georgia about 30 years ago. It ... | |
| Lab Report | 4/14/2007 |
| Q: I did on experiment to determine the coefficient of friction of wood on wood. So now I am writing a ... A: How about a hypothesis that it's going to take some force to pull one piece of wood across another ... | |
| Energy due to charge | 4/12/2007 |
| Q: Two protons are brought towards each other. will the potential energy of the system increase or ... A: If two protons are brought towards each other the potential energy increases since it takes work to ... | |
| Physics | 4/10/2007 |
| Q: A set of parallel plates in a cathode ray tube is 17.8 cm long, and the plates are 3.45 cm apart. ... A: Yes, you can think of it as firing a gun horizontally and the bullet dropping due to gravity. First ... | |
| friction | 4/10/2007 |
| Q: frictional force acts to oppose one surface from sliding relative to the other with which it is in ... A: Friction can be both good and bad. If you're sliding something along a surface you want the ... | |
| Incline Plane | 4/10/2007 |
| Q: When we learn about Inclined plane, we have two coordintates, mg, mgsin(teta) and mgcos(teta). 1.mg ... A: mg acts straight down but to calculate the forces acting on a body on an inclined plane, you need to ... | |
| Electricity | 4/10/2007 |
| Q: I am having difficult with the following problem: Object I has a charge of +3*10^-6 coulomb and a ... A: The first parts are okay. For the magnitude and direction of the electric field midway, simply ... | |
| Mechanics | 4/10/2007 |
| Q: I am a little confused with the followingA pendulum consists of a small object of mass m fastened to ... A: First of all, a pendulum will swing back and forth with a certain period regardless of the angle ... | |
| plzzzzzzzz answer me very soon.... | 4/6/2007 |
| Q: my questions are Q1. Describe all the forces acting upon a ladder that is leaning against a wall. ... A: Q1. There is a force that the floor exerts against the ladder and a force that the wall exerts ... | |
| Electricity | 4/4/2007 |
| Q: I have some follow-up questions from our last exchange: Hi! I have another question from a past AP ... A: 1) the batteries oppose one another so that's why it's 18. The 2 volt battery is being charged by ... | |
| Electricity | 4/4/2007 |
| Q: I have another question from a past AP Physics B Exam (I'm preparing for the exam in May!) The ... A: Yes, the equivalent resistance of the circuit is 4+R so (4+R)(2) = 18 and R = 5 ohms. the ... | |
| i want answers very soon. | 3/27/2007 |
| Q: Q1. Scientists are told to doubt everything and not believe anything that is not provable. Is this ... A: Q1. I think it's a strength. Q2. already answered this Q3. Obviously, the angle between the two ... | |
| plzzz answer it soon..... | 3/27/2007 |
| Q: question is Suppose we measure time by using hour glasses filled with sand. Discuss the various ... A: Obviously it would depend on how accurately one glass measured an hour. Any error would propagate ... | |
| Newton's law of gravitation | 3/15/2007 |
| Q: Can you see if my strategy for this problem is a good one or not. First the problem, An object is ... A: The final velocity is going to be greater than that since g increases as the object approaches the ... | |
| mass energy equation | 3/12/2007 |
| Q: before u read the questions i apologise for asking so many detailed questions. bUt please do reply. ... A: 1. I cannot explain E = mc^2 without referring to nuclear reactions since that's the only place ... | |
| acceleration due to gravity | 3/12/2007 |
| Q: Why is the value of acceleration due to gravity(g) more at the poles than at equators? Why does the ... A: gravity varies with the distance from the center of the Earth so that's the answer to your first ... | |
| physics | 3/5/2007 |
| Q: why does an object on mass m gains mass when it travels with the speed of light? I know it is ... A: It's called relativistic mass since the object doesn't get any bigger in size. Anything with mass ... | |
| Velocity of radiation | 3/5/2007 |
| Q: What is the velocity radiation in a vacuum? Does the type of radiation effect the velocity? Also, ... A: Nuclear decay such as nuclear fission, fusion or unstable molecules can produce gamma radiation but ... | |
| science project | 2/28/2007 |
| Q: My friend and and I are doing a science project and we need to demonstrate momentum. However, we do ... A: momentum is the product of mass times velocity. M = mv. Some novelty stores sell a momentum ... | |
| physics | 2/24/2007 |
| Q: Im joyce. am asking for your help.. Sad to say, i can hardly understand Physics sub.. Our topic is ... A: 1. In physics we prefer to stick to metric units. 1 Hp = 746 watts = 746 joules/s PE = mgh = ... | |
| Center of Mass | 2/23/2007 |
| Q: I see where the 300=v1+12v2 comes from, but am having trouble seeing how V2-V1=300 was derived.A ... A: For an elastic collision you have momentum conserved and energy conserved. So you have v1i and v2i ... | |
| Elecricity | 2/22/2007 |
| Q: When current is flowing in a wire, can we say that wire is charged ? A: No. When we say something is "charged" we usually mean there's a separation of charge and one part ... | |
| physics | 2/18/2007 |
| Q: why is a swimmer not hurt, while diving in deep water tank? A: Why should she be hurt? You're not asking a physics question. I've answered over 2000 questions on ... | |
| physics | 2/7/2007 |
| Q: why does sound travels slower in denser mediums, for example sound travels faster in wood than steel ... A: Sound travels as a longitudinal wave in which the molecules bump into each other along the way. So ... | |
| physics | 2/7/2007 |
| Q: Wha is young's modulus? why are solis considered to have more elasticity than liquids and gases? ... A: Young's modulus is property of a material, just like density. It's related to stress and strain. ... | |
| physics | 2/7/2007 |
| Q: The velocity of a wave is given as ?ãE/?ãd where E = elasticity of the medium and d is density of ... A: Your equation came through garbled. My textbook shows the velocity of sound in a liquid to be ... | |
| physics | 2/6/2007 |
| Q: what is effective length of a bar magnet? Why is it called so? Why is effective length less than the ... A: A bar magnet is so called since it's shaped like a bar. It can be any size. It's just the nature ... | |
| very simple question | 1/31/2007 |
| Q: i have one question, i admit it is simple, but i can take either way on it. does initial velocity of ... A: No, they are entirely separate. For objects subject to the gravitational pull of the Earth, the ... | |
| Physics Kinematics in one dimension | 1/31/2007 |
| Q: I am so stumped on this one! Usually, I have a clue about waht equations to start with, but this ... A: First of all, you need to convert from km/h to m/s. 45km/h = 12.5m/s 65km/h = 18.06m/s A) Even at ... | |
| Gauss's Law | 1/30/2007 |
| Q: I have a (three-part) question on Gauss’s Law. If you enclose a dipole in a spherical Gaussian ... A: My book talks about deriving Gauss's Law with a point charge, q, enclosed by a surface S to get the ... | |
| Projectiles | 1/24/2007 |
| Q: At 1/2 of its maximum height the projectile is 3/4 of its original speed. What is the launch angle. ... A: If the launch angle is A and the initial velocity is V, then the initial velocity in the x direction ... | |
| Physics | 1/22/2007 |
| Q: I am sure this is something really easy that I am simply overlooking but here it is: Margaret has ... A: Let's say the distance upstream or downstream is x. Therefore, the current in the stream is x/8 ... | |
| Physics | 1/19/2007 |
| Q: A skier is gliding along at 3 m/s on horizontal frictionless snow. He suddenly starts down a 10 ... A: KE at bottom = KE at top +mgh where h is the height of the incline. Since the mass cancels out you ... | |
| please help | 1/7/2007 |
| Q: The problem is that there are 2 blocks connected by a string (that has the same mass everywhere in ... A: First of all, the tension is the same throughout the rope, otherwise it would break. All three ... | |
| ball | 12/31/2006 |
| Q: how does the height of a ball drop affect the bounce height? what is its independent and dependent ... A: The bounce height is related to the original height by the coefficient of restitution, e. It's ... | |
| Vector & Flux | 12/30/2006 |
| Q: The resultant will be vector or scalar? I say the Electric flux is defined as the number of electric ... A: If you define a certain area, then there's no element in that area that doesn't have electric field ... | |
| newton | 12/29/2006 |
| Q: Did Newton state his 2nd law of motion as F=Ma OR as F=dP/dt? I know the second is more general ,but ... A: Newton stated it "The change of motion is proportional to the motive force impressed; and is made in ... | |
| Friction | 12/28/2006 |
| Q: What is difference between 'sliding' 'rolling' 'slipping' of a body when friction is considered ? ... A: The forces due to friction vary depending on the motion of the body. Obviously, a rolling ... | |
| help plz | 12/21/2006 |
| Q: here's thewhy is the water supply tank in a town made at suffiecient ht.?my book says its coz then ... A: For every 30 feet of height in a water tank the pressure increases by about 15 lb/in^2. Since the ... | |
| help plz | 12/21/2006 |
| Q: here's theacc to the formula pressure=hdg pressure is independent of the area of the surface on ... A: the amount of force a block exerts on a surface is a function of the mass of the block, independent ... | |
| help plz | 12/17/2006 |
| Q: can u plz help me out with this question? when a floating piece of ice melts into water it contracts ... A: Ice is less dense than water. That's why it floats. Any floating object sinks until it displaces ... | |
| physics-simple harmonic motion | 12/15/2006 |
| Q: what exactly do u mean by- equation of a simple harmonic motion? what is it's significance? A: Think of a child swinging back and forth. The projection of the child's path on the ground ... | |
| voltage vs current | 12/5/2006 |
| Q: i made a lemon battery by connection about 24 lemons in series and get a voltage of about 20 volts. ... A: It's the chemical reaction inside that produces the energy. Sorry you felt like I didn't give you ... | |
| Physics | 12/5/2006 |
| Q: 1. Which of the following will result in a chemical change? A. Melting ice to obtain water B. ... A: I don't know where you're getting your answers but you didn't do a very good job on these. 1. D ... | |
| hair dryers | 11/20/2006 |
| Q: hey can you please tell me how hair dryers work? and how electricity is invloved in it? A: Light bulbs get hot in addition to producing light. The elecricity passes through a resistor in the ... | |
| Decay Equation for Pendulum | 11/16/2006 |
| Q: Richard. That's correct, I'm referring to the decay in height as the pendulum swings. If the ... A: Sure, e^2 would still be a constant. You must have pretty sharp eyes if you can detect a change in ... | |
| Decay Equation for Pendulum | 11/15/2006 |
| Q: I'm looking for a basic equation to describe the decay of a swinging pendulum. I remember it ... A: I assume you're not talking about the period changing as a function of time since that doesn't ... | |
| impulse and momentum | 11/13/2006 |
| Q: A 1055 kg van, stopped at a traffic light, is hit directly in the rear by a 740 kg car traveling ... A: let v = velocity of van after collision and c = velocity of the car after collision 740(1.95) = 740c ... | |
| inductors | 11/12/2006 |
| Q: I understand that an instaneous change in current would imply infinite voltage drop, which doesn't ... A: Since electricity travels with the speed of light, you can have a near instantaneous change in ... | |
| inductors | 11/11/2006 |
| Q: I am learning about the properties of inductors. I read that changes in current through an inductor ... A: It may not make sense to you but that's the way inductors work. The self-inductance in a circuit ... | |
| Magnets | 11/10/2006 |
| Q: I have been told that a magnetic field is strongest at the poles of a magnet and weakest in the ... A: Regardless of the size of the magnets the strengths of the two poles are the same. It's simply the ... | |
| Fluids & Pressure | 11/7/2006 |
| Q: Good evening Mr. Raridon, I'm having some problems with this question, I have (I think) figured out ... A: Since the density of Hg is 13.6, 1 meter column of water exerts the same pressure on the bottom as ... | |
| nuclear power | 11/6/2006 |
| Q: i have a few of questions to ask. When exactly will nuclear power run out? how many nuclear power ... A: Nuclear power will not run out for many, many years, especially if you breeder reactors which create ... | |
| work and energy | 11/2/2006 |
| Q: Yes I tried it but i am confused the distance from A to B is .500m and the distance from B to c is ... A: So now you have calculated F(AB), F(BC) and F(AC). mA is being attracted by both mB and mC so the ... | |
| Law of Attraction | 11/1/2006 |
| Q: Two more quick questions on the subject, since I bought some alloy tuning fork sets and the demo did ... A: A hollow box helps amplify the sound, especially if you have two boxes and point them toward each ... | |
| Law of Attraction | 11/1/2006 |
| Q: I'd like to do a simple demonstration of the Law of Attraction (like vibration attracts like ... A: Yes, another tuning fork at the same frequency will vibrate but they have to be fairly close ... | |
| Physics | 11/1/2006 |
| Q: A fighter jet is launched from an aircraft carrier with the aid of its own engines and a ... A: You could write the thrust as 1.90x10^5N and the kinetic energy as 4.10x10^7J The work done by the ... | |
| physics help | 10/30/2006 |
| Q: The moon has a mass of 7.4x10^22 kg and copletes an orbit of radius 3.8x10^8 m about every 28 days. ... A: You should be able to answer those. The circumference of the moon's orbit is 2(pi)(3.8x10^8) and ... | |
| spin balancing tires | 10/30/2006 |
| Q: Just bought a new set of tires and noticed that they caution you never to exceed 35 mph on the ... A: You might ask your tire dealer. If you are stuck on ice then you're obviously not moving. If your ... | |
| Curvature | 10/29/2006 |
| Q: A car rounts a banked curve where the radius of the curvagure of the road is R=100m, the banking ... A: The weight of the car, mg, acts straight down and the centrifugal force acts horizontally. Consider ... | |
| Simple Harmonic Motion | 10/29/2006 |
| Q: If a particle moves in simple harmonic motion with a frequency of 3.00 Hz and an amplitude of 5.00 ... A: Total distance = 10 cm let w be the symbol for omega, so that w = 2(pi)f y = Asin(wt) = 5sin[6(pi)t] ... | |
| momentum | 10/22/2006 |
| Q: Could you explain what momentum is actually? I know it's a mass having a velocity but if someone ... A: momentum = mv. One measure of momentum is the force required to stop it. mv = Ft which is called ... | |
| rotational motion and the law of gravity | 10/19/2006 |
| Q: I don't know how to even start the following question. i need few pointers. the question is the ... A: the acceleration due to gravity will be less at that altitude. 9.8(6370)^2 = a(6570)^2 so a = ... | |
| uranium update | 10/18/2006 |
| Q: but I'm confused; Not all atoms split? I thought splitting an atom was a natural process and when ... A: I don't know where you heard that all atoms split, but it's just the opposite. In nature, no atoms ... | |
| uranium update | 10/18/2006 |
| Q: I asked a question about uranium and what was "enrichment" the other day and would like to ask a ... A: No, all atoms don't split. In fact, to get energy from a fusion reaction, you have to combine ... | |
| conductor | 10/15/2006 |
| Q: WHY SHOULD THAT CONDUCTOR/METAL SHOULD OBEY OHM'S LAW?why should any conductor obey ohm's law? ... A: Ohm's law states that the voltage across a conductor is proportional to the current through it. V = ... | |
| physics | 10/15/2006 |
| Q: what are the quantum and classical laws that an electron obeys? A: Each electron in orbit about an atom has four quantum numbers which are determined by the properties ... | |
| uranium | 10/15/2006 |
| Q: With everything going on in the news I keep coming across the term "enriching uranium" in layman's ... A: Uranium, as its mined from the ground, consists of two main isotopes, U-235 and U-238. They both ... | |
| Atomic Number | 10/15/2006 |
| Q: Can you tell me what would happen to the atmoic number and mass number of a nucleus when it emits a ... A: The mass number of a nucleus doesn't change since positrons and electrons have very little mass. ... | |
| physics | 10/12/2006 |
| Q: an amuse ment park ride consists of alarge vertical cylinder that spins about its axis fast enough ... A: I use u for the coefficient of friction since it's really the Greek letter mu. So u times the ... | |
| Newton's Law & Rocket Motion | 10/12/2006 |
| Q: A rocket is travelling at CONSTANT SPEED. Q1. Is there change in momentum Q2. What is the net force ... A: If an object is traveling at a constant speed, in a STRAIGHT LINE, then there is no net force acting ... | |
| Egg drop | 10/10/2006 |
| Q: What basic underlined principals are involved in a typical physics class egg drop? A: As the egg drops it obeys the laws of falling bodies, v = gt, S = (1/2)gt^2, KE = (1/2)mv^2 and ... | |
| physics help | 10/2/2006 |
| Q: sorry to bother u again but there is another problem i am unsure of how to solve i have the answers ... A: You always want to draw a picture of the problem. the ball is in equilibrium which means the sum of ... | |
| physics help | 10/1/2006 |
| Q: I have a huge exam on Monday and ther are like 3 questions that i can not figure out how to solve. I ... A: (a) average speed = total distance/total time = (147.2+59.5)/2.1 = 98.4km/h (b) Here you have to use ... | |
| Physics | 9/30/2006 |
| Q: I am working with some gifted middle schoolers on a Science Olympiad project. In the project ... A: That's about it. The egg is accelerating due to gravity as it drops. It has to decellerate ... | |
Physics
Answers by Expert:
Richard J. Raridon
Top Expert on this page
Expertise
I can answer most questions in undergraduate physics courses, including electricity and magnetism, atomic and nuclear, mechanics and optics.
Experience
I have taught undergraduate physics courses
Organizations
Sigma Xi, AAAS, SE section of APS
Education/Credentials
BA in math, MA in physics, PhD in physical chemistry
Awards and Honors
Fellow of AAAS
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