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# Physics/Physics Olympics Project

Question
QUESTION: I am in grade 10, and we have a physics project by group. We have catapult making, egg drop, balloon-powered car, water rocket launching, centrifuge water, paper tower and bridge making.

I was searching but I could not find answers that would best help me for the catapult making, egg-drop, and centrifuge water.

For the catapult, I must use any recycled material  with  the size as 12x6x6. For every cubic cm excess there will be deductions.
For the egg-drop, I must use one broadhsheet newspaper, egg in plastic, 2 metres of yarn and 1.5 metres of adhesive tape. No other requirements, however no damage would result in perfect points with 5 points deductions, the greater the damage
For the centrifuge water we need a plastic cup. cardboard and yarn...we must make a 2-minute choreography. How do I do that?
As for the PET rocket making, how can I make the fins better and how can the rocket fly really high?

Sorry for the long message.
Thanks

ANSWER: I'm a little unclear.  Were you asking for advice on the whole thing, or just the three in the middle of your question?  I have advice on a lot of projects, I just need to know if you need advice on all categories and some parameters on what they mean.

For the three you mention, I would assume you can make any catapult type you want.  That opens it to trebuchets or flexible catapults.  Flexible designs are far more effective at that tiny size scale, so go with something small and flexible like a plastic ruler set.  If you want a trebuchet design, then use pulleys or rubber bands to amplify the power...store energy in your catapult with the rubber bands to pull down the opposite end, experiment with the position of the fulcrum.

For the egg drop, that's easy.  Make sure the yarn is on top and that the big crush zone is on bottom.

For the centrifuge water...is this an art display?  The best dance thing I can think of is to ignore the cardboard and to just pour the water into the cup at the start, come up with a 2-minute dance routine (set it to music so that you have the timing right and PRACTICE), and then pour it out into another clear container at the end.  Cardboard....really won't help you there.

---------- FOLLOW-UP ----------

QUESTION: Well for the other categories, I found help on the internet but if you could add some more advice it would be really helpful.

For the centrifuge water, it's not an art display, but just our teacher challenging us with physics and dancing together since he did that in college. Problem is, I don't know any technique in keeping the water in the cup without it spilling.

http://www.youtube.com/watch?v=pMQzSZdjrz8 is the link he gave us but I don't know what kind of technique to use.

You just swing it around.  It's centripetal force.  It doesn't have to be balanced on a flat platform and made of glass, that was just for effect by someone who'd practiced it.  Just hook up some plastic cup to some strings, swing it, and swing it all the way around like the guy in the video.  It's more art than science.

Physics

Volunteer

#### Dr. Stephen O. Nelson

##### Expertise

I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.

##### Experience

I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Education/Credentials
Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.