Self Propelled car help?

Question

i have a project where i have to make a self propelled car everything that can give it the force to go has to be on the car when it is moving so no sling shot or push or anything and i was just wondering if i could get some good tips

Answer 1

A mouse trap car is a classic small scale self propelled vehicle... I did that once.

is battery + electric motor forbidden?

You could try some sort of rubber-band potential energy setup with a lever and gears

If you can use heat, then try a reaction that produces steam. An example might be sodium + water or the substance used in MRE's (e.g. there is a chemical reaction when you add water to the MRE that heats the food - use a similar chemical to heat water to a boil for steam) Use the steam to drive a paddle on the axle of your car.

Goodness... lots of ways... if these won't help, I'll check back later and toss some other ideas your way.

-Edit: The basis of a mouse trap car is the use of the spring energy of a mouse trap to propel a small scale vehicle. I have seen this done multiple ways. In one case, the mouse trap turns a series of pulleys which turn a driving wheel. In another the trap will sling an object off of the vehicle. There is a transfer of momentum in this case which propels the vehicle. You can be pretty creative, even go as far as a sort of Rube Goldberg contraption... Of the two I suggest, the first should be relatively heavy so that the trap does not spin out the wheels, and the second must be light (with a heavy weight) so that the momentum transfer results in a useful velocity. The later is way more physics'y and so kind of fun. In fact, this is basically how the space shuttle works - it flings gasses at high speeds in one direction to propel it in the opposite direction. Plus - technically its not a slingshot and is 100% self propelled, so it fits your parameters.