A pitcher throws a fastball with a speed of 45 m/s towards home plate. The batter swings his bat (mbat = 0.94 kg) with a speed of 47 m/s and hits the ball (mball = 0.145 kg) in the opposite direction with a speed of 50 m/s. The time of contact between the bat and the ball is 0.7 milliseconds (0.0007s).



What is the kinetic energy of the system immediately after the bat hits the ball?