A skateboarder with a mass of 67.0 kilograms (including the skateboard) rolls down from the top of a ramp, reaching a velocity of 7.30 meters per second at the bottom of the ramp. Assuming friction is 0, what was the potential energy of the skateboarder at the top of the ramp?
1,785 J.
59.70 J.
74.30 J.
489.1 J.
