Questions about this mousetrap car? come on..i am desperatly in need of help?

Question

first would this go at least 2m. i am going to try to make this one. would it get good speed and distance. any way to modify it so i can go really far, really fast. thank you.

http://www.mousetrap-cars.com/kevins.jpg

Answer 1

These are just guesses on my part, but here's what I see when I look at that car:

It's light, so it is easy to start, but it doesn't have enough mass to sustain momentum for a great distance.  You would like to have a heavier car, so that (once it gets going) it will travel farther.  However, weight will make it slower (but go farther).

Also, in order to compensate for the car's light weight, he used large sponge rear tires for better traction at launch.  However, after launch, the wheels will have significant rolling resistance and slow the car down.

I would go with larger, heavier wheels that are narrower.  Maybe 10cm tall, and a cm wide, with the rear wheels having hard rubber tires and the front ones maybe with tires or bare (less rolling resistance)  They will act as gyroscopes, once they start spinning, they keep going.  Make the rest of the car identical to Kevin's, a lightweight chassis (all the weight in the wheels).  I would use the same length rod attached to the mousetrap, but use maybe a 1cm-wide dowel for the rear axle, and wind the thread around this thicker axle, giving you a better "gear ratio."  You will need to experiment with axle sizes - try something smaller and build its width with tape, testing the distance with each axle thickness.

Good luck!  Slow and steady rules in the mousetrap inertia world!