Halliday, Resnick & Walker — Motion Along a Straight Line: Problem 85

Fastball timing. In professional baseball, the pitching distance of 60 feet 6 inches is the distance from the front of the pitcher’s plate (or rubber) to the rear of the home plate. (a) Assuming that a 95 mi/h fastball travels that full distance horizontally, what is its flight time, which is the time a batter must judge if the ball is “hittable” and then swing the bat? (b) Research indicates that even an elite batter cannot track the ball for the full flight and yet many players have described seeing the ball−bat collision. One explanation is that the eyes track the ball in the early part of the flight and then undergo a predictive saccade in which they jump to an anticipated point later in the flight. A saccade suppresses vision for 20 ms. How far in feet does the fastball travel during that interval of no vision?