mousetrap car design help

Questions:

How can I get the maximum power output from my mousetrap powered car?

Answer:
When you build a mouse-trap car for distance, you want to have as small an energy consumption as possible. Smaller power outputs will produce less wasted energy and greater efficiency. When you build a vehicle for speed, you want a large power output. You can change the power output ratio of your vehicle by changing one or all of the following: the length of the mouse-trap's lever arm, the drive wheel diameter, or the drive axle diameter.

The amount of energy used by a short lever arm and a long lever arm are the same, but the distance that the energy is used determines that rate of energy consumption or the power. Long lever arms decrease the pulling force but increase the pulling distance, thereby decreasing the power. Short lever arms increase the pulling force and decrease the pulling distance, thereby increasing the power.

If you are building a mouse-trap car for speed, you will want the maximum power output just before the point where the wheels begin to spin-out on the floor. Maximum power output means a higher rate of stored energy is being transferred into energy of motion or greater acceleration of the vehicle. Greater acceleration can be achieved by having a short length lever arm or by having a small axle to a large wheel.

If you are building a distance vehicle, you want to minimize the power output or transfer stored energy into energy of motion at a slow rate. This usually mean having a long lever arm and a large axle-to-wheel ratio. If you make the lever arm too long, you may not have enough torque through the entire pulling distance to keep the vehicle moving, in which case you will have to attach the string to a lower point or change the axle-to wheel ratio.

See the following related articles to get started:

• basic mousetrap vehicle propulsions (how to make it move)
• making a good distance traveler
• making a good speed-trap racer