[填空题]
A 0.145-kg baseball pitched at 39 m/s is hit on a horizon(q,zg, zcp xcm/r5g8 +txgst5z ,w;h vtal line drive swk9e;j jbc-zf 7msmxso 0z8n,-6 9duj traight back toward the pitcher at 52m/s If the conjm-ns-u d 0s6e 8f 9,zkoxjzmjcw;7b9tact time between bat and ball is $3\times10^{-3}$s calculate the average force between the ball and bat during contact. N
