Just before a baseball is hit by a bat, it has a velocity of 30 m/s, 15A??o below the +x axis. After it is hit by the bat, it has a velocity of 60 m/s, 30A??o above the -x axis. If the bat is in contact with the ball for 4 ms, what is the magnitude of the average acceleration of the ball while in contact with the bat? Please show the work that leads to the answer.