Physics Analysis

After doing calculations, we were able to find our mousetrap car's potential and kinetic energy.

Kinetic Energy: 1/2(mass)(velocity)^2
                            1/2(.192)(1.49)^2
                            =.2131 J
Potential Energy: (avg. force)(distance of string)
                          (2) (.055 * 3.14)
                          =.3454 J

These calculations make sense because while the kinetic energy is less than the potential energy of the mousetrap spring, friction in the wheels and body of the car will cause the thermal energy to rise and the kinetic energy to decrease. The length of the lever arm was multiplied by the average force to find our potential energy which makes sense since it is half of the length of the mousetrap itself. The efficiency of our mousetrap car is 61.7%.

Because this mousetrap spring is not that strong, it makes sense that both the Kinetic and Potential Energy are low values. The Total Energy never changes, but instead converts between Kinetic, Potential, and Thermal Energy (created by friction).

Our greatest problem dealing with friction was between the axles and body of the mousetrap car. The axles turning would create friction against the cardboard body and convert some of the spring's Potential Energy into Thermal, instead of Kinetic Energy that would make the car accelerate.