单项选择题
A 57-g tennis ball is traveling straight at a player at 21 m/s. The player volleys the ball straight back at 25 m/s. If the ball remains in contact with the racket for 0.060 s, what average force acts on the ball?
A. 22.6 N
B.32.5 N
C.43.7 N
D.72.1 N
E.102 N