When a soccer ball is kicked toward a player and the player defiects the ball by " iteading" it, the acceleration of the head during the collision can be significant. Figure 2-23 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)=200m//s^(2)`. 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 ?

Answer

0.56 m/s