Function

• The wheels on a mousetrap car are driven by a string or rubber band wound around the axle. When the mousetrap is triggered, it pulls the string and makes the axle spin around very fast. How far and how fast the car goes depends greatly on the wheels.
  
  

Considerations

• One of the main considerations is the size of the wheels. The axle can only be made to turn so many times before the energy from the spring is exhausted. Big wheels allow your mousetrap car to travel further, as each turn of the axle translates into a greater distance. (Note that only the rear wheels need to be large.) The wheels should also be as light as possible.
  
  

Materials

• Old vinyl records can be used as wheels. They are large and relatively light. Other options include plastic plates and wheels cut from card stock or craft foam.