The average velocity of the ball between first contact with the glove and when it stops is 25/2 = 12.5 m/s. The time that the ball is decelerated is T = D/12.5 m/s, where d is the distance that the glove moves backwards.
The average force is given by the momentum law
(avg. Force) * T = initial momentum
avg. Force = M V*(V/2)/D = K.E./D
This is another way of saying that the ball does work on the backwards-moving glove that equals the initial kinetic energy of the ball.
A catcher “gives” with the ball when he catches .15 kg baseball moving at 25 m/s. (a) If he moves his glove a distance of 2.0 cm, what is the average force acting on his hand? (b) Repeat for the case in which his glove and hand more 10 cm.
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