Assume that a 15-kg ball moving at 8 m/s strikes a wall perpendicularly and rebounds elastically at the same speed. What is the amount of impulse given to the wall?
Mass of the ball is m = 15 kg Velocity of the ball is v = 8 m/s The momentum of the ball is P = mv = (15 kg)*(8 m/s) = 120 (kg-m)/s Because the ball rebounds elastically, its rebound velocity is 8 m/s in the opposite direction. The change in momentum of the ball is 2P = 240 (kg-m)/s. The impulse on the wall is equivalent to the change in the momentum of the ball, so it is 240 (kg-m)/s Answer: 240 (kg-m)/s