Science Project

[sciencerox]

My science teacher wants us to make a rubberband powered car which holds an egg and can run for 4 metres. I need to ask, what affects the distance and speed and how to I make sure that the car runs exactly for 4 metres.

[ronthepon]

Exactly 4 meters is too difficult. You will really have to work real precisely for that.

[Jay-qu]

you would be best to mark how far you have to wind the elastic to make the car travel 4m and then reproduce that same windage when required

[sciencerox]

Thanks for the suggestions. Can you suggest to me where would be the better place to put something to hold the egg?

[Jay-qu]

cardboard/plastic box, what ever you can find that is lighter and is large enough to hold an egg - then fill it will cotton buds if it *has* to stay intact.

[sciencerox]

Should the car be small or big??

[Jay-qu]

up to you really, depends on the type of elastic band you get, you may have to run a few tests see if you can actually get the car to run the distance required. I suggest that it be as light as possible though, unless you have trouble with the car going to far, they you could weigh it down a little.

[sciencerox]

thanks

[sciencerox]

would these type of cars run that far?

[InfiniteNow]

Bear in mind that... the more you test your car, the less it will travel.

 

The rubber band begins to lose elasticitiy. Not usually a big deal, but if your teacher wants it to go EXACTLY 4m, it may be worth noting.

[UncleAl]

Setting length of travel is easy: string + axle. The hard part is the power source. Friction is your enemy. Hooke's law for the rubber bands, then energy equals force times distance. You'll need some clever leverage to convert short and large to long and easy.