We chose CDs to be the wheels as Cds have an average diameter of 12cm. They also have a central hole which is around 1.5 cm wide. Balloons will be cut up and pasted onto the sides of the wheels to increase the traction of the wheels.
The chassis of the car will be made out of balsa foam wood as it is lightweight yet strong. We will try to reduce as much weight as possible by using wood only in places crucial to the car's structural integrity.
Lever arm and string type
The lever arm should be of a medium length. This is to ensure that there is enough length in the string to travel the 8 metres required but must be able to fit within the 30cm limit. The string that we will be using is nylon fishing line. We chose nylon fishing line as it is thin yet strong. This lessens the chance of it being stuck onto something.
The axle is a key factor to the car's speed as it is where the kinetic energy of the lever arm is used to spin the wheels, propelling the car forward.
Positioning of mousetrap
The mousetrap should be put at the frontmost part of the car facing forward. This is to ensure that the lever arm is as close to the axle as possible when wound up.
The body of the car