posted by Anonymous .
A typical baseball has mass of 150 grams. Suppose a batter hits a fastball pitched to him at 92 mph (which is about 40.89 m/s). After contact, the ball's speed is measured as 104 mph (which is about 46.22 m/s) directly back at the pitcher (who is able to duck out of the way, barely). The length of time that the ball is in contact with the bat is 0.002 s. During this time, the only force that is important for the ball's motion is the normal force applied by the bat. Calculate both the ball's acceleration and the force applied on it during this time. (We'll approximate the acceleration and force as constant, which is probably not quite true, but close enough for this problem.)
F = m*a = 0.15 * 2665 = 399.75 N.