Explain how the energy of a rubber ball is transformed as it rolls down a ramp. give evidence that the energy of the ball remains the same at all points on the ramp.

Arailroad car collides with and sticks to an identical railroad car that is initially at rest. after the collision, the total kinetic energy of the two cars is a) the same as before. b) half as much as before. c) one third as much as before. d) one fourth as much as before. e) twice as much as before.