How to build a rubber band car instructions

Key concepts
Physics
Potential energy
Kinetic energy
Conservation of energy
Simple machine

Introduction
Admit it, you’ve probably launched a rubber band at least once—pulled one end back, and let it go flying. Did you ever suspect that rubber bands could also be a fun way to learn about physics and engineering? Find out in this project where you’ll build a rubber band–powered car.

Background
When you stretch a rubber band it stores potential energy. Specifically it stores elastic potential energy—the type of energy stored when a material is deformed (as opposed to gravitational potential energy, the type you get when you raise an object off the ground). When you release it all, that stored energy has to go somewhere. If you launch a rubber band across the room, the potential energy is converted to kinetic energy, the energy of motion.

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But what about putting all that stored energy to use? You can attach your rubber band to a simple machine—a wheel and axle—to build a simple rubber band–powered car. In real cars, gasoline’s chemical energy or the electrical energy in a battery is converted to kinetic energy of the moving car. Your model car will use a rubber band as the source of energy. It will take a little engineering to get your vehicle working—challenge yourself to see how far your car can go!

Materials
(Note: This is an engineering design project. The following is a suggested list of materials, but you can substitute different ones.)

Preparation