A0.060-kg tennis ball, initially moving at a speed of 12 m/s, is struck by a racket causing it to rebound in the opposite direction at a speed of 18 m/s.

what is the change in momentum of the ball?
a) 0.72 kg·m/s

b) 0.36 kg·m/s

c) 1.1 kg·m/s

d) 1.8 kg·m/s