# physics

posted by on .

A ball rolls up a ramp which abruptly ends with the ramp dropping straight down. The ball launches off the end of the ramp while still traveling at an upward trajectory, goes through projectile motion, and returns to the same height as the base of the ramp. Ignoring any slowing friction (rolling friction), when the ball returns to the height of the ramp's base, the ball lands with a greater speed than when it entered the ramp. Explain why

• physics - ,

The question gave a hint, it mentioned rolling friction, meaning that the ball rolls without slipping.

Do you think the ball spins faster when it was at the bottom of the ramp than at the top? Why does that happen? Where does the spinning energy go?

• physics - ,

As I interpret your description of what is happening, the situation is not possible. Conservation of energy is violated.

• physics - ,

MathMate raises a good point. Total KE of the ball remains the same, but it is rotating at a slower rate at the top of the ramp, and keeps this rate when it hits the ground. This increases the translational KE and speed when it hits the ground.