A baseball (m = 0.14 kg) has an initial velocity of v = -26.9 m/s as it approaches a bat. We have chosen the direction of approach as the negative direction. The bat applies an average force F that is much larger than the weight of the ball, and the ball departs from the bat with a final velocity vf = +44.7 m/s. Assuming that the ball's time of contact is t = 8.36 * 10^-3 s, find the average force (in newtons) exerted on the ball by the bat.