# Physics

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A boxer punches a 50 Kg bag. Just as his fist hits the bag, it travels at a speed of 7 m/s. As a result of hitting the bag, his hand comes to a complete stop. Assuming that the moving part of his hand weigh 5 Kg, calculate the rebound velocity and kinetic energy of the bag.

• Physics -

Momentum is conserved. initial momentum of the fist, that has to equal the final momentum of the bag. Calculate its velocity, then its KE.

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