# (a) Explain why a cricket player moves his hands backward while catching a fast cricket ball.(b) A 150 g ball, traveling at 30 m/s, strikes the palm of a player’s hand and is stopped in 0.05 seconds. Find the force exerted by the ball on the hand.

(a) A player moves his hands backward while catching a fastball because a fast-moving ball has a large momentum and in stopping this ball, its momentum has to be reduced to zero. Now, when a cricket player moves back his hands-on catching the fastball, then the time taken to reduce the momentum of the ball is increased. So, the rate of change of momentum of the ball is decreased and hence a small force is exerted on the hands of the player and the hands of the player do not get hurt.

(b) Here Mass of ball$=150\ g=0.15\ kg$

Initial velocity $u=30\ m/s$

Final velocity $v=0\ m/s$

Time $t=0.05\ s$

Acceleration, $a=\frac{v-u}{t}$

$=\frac{0-30}{0.05}$

$=-600\ m/s^2$   [-ve singn indicates the negative acceleration or retardation]

Therefore, force exerted by the ball on the hands $F=ma$

$=0.15\times600$

$90\ N$

Updated on: 10-Oct-2022

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