Chapter 2, Problem 67P

When a soccer ball is kicked toward a player and the player deflects the ball by “heading” it, the acceleration of the head during the collision can be significant. Figure 2-38 gives the measured acceleration a(t) of a soccer player’s head for a bare head and a helmeted head, starting from rest. The scaling on the vertical axis is set by a_s = 200 m/s². At time t = 7.0 ms, what is the difference in the speed acquired by the bare head and the speed acquired by the helmeted head?

Figure 2-38 Problem 67.