You are hitting a tennis ball against a wall. The 0.057-kg tennis ball traveling at 30 m/s strikes the wall and rebounds at the same speed. Earth is the object of reference.

1. Determine the ball's original momentum (magnitude).

2. Determine the ball's change in momentum (magnitude).

Answer

given,

mass of the tennis ball, m = 0.057 Kg

speed of the ball, v = 30 m/s

rebound speed, v' = - 30 m/s

a) original momentum of ball

P = m v

P = 0.057 x 30

P = 1.71 kg. m/s

b) change in momentum

P = m v - m v'

P = 0.057 x 30 - 0.057 x (-30)

P = 3.42 kg. m/s

We have use - 30 m/s velocity because motion of the ball is in opposite direction.