A student designs an experiment where he takes a small wood car with 1.0 inch diameter wheels and rolls it down a ramp. The student measures the speed of the car when it reaches the bottom of the ramp. The student then takes a small plastic car with 1.5 inch diameter wheels and repeats the process. Finally, the student takes a small metal car with 2.0 inch diameter wheels and repeats the process a final time. The student notes that the metal car had the fastest speed at the bottom of the ramp.