A 032-Kg Ball Is Moving Horizontally at 30 M/s Just Before

Short Answer

A 0.32-kg ball is moving horizontally at 30 m/s just before suddenly bouncing off a wall
Just after the bounce, it is moving horizontally at 25 m/s but in the opposite direction.
(a) What is the magnitude of the change in momentum of the ball during the bounce?
(b) What percentage of the ball's original kinetic energy was lost in the collision?