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A boy of mass 25 kg stands on a board of...

A boy of mass 25 kg stands on a board of maas 10 kg which in turn is kept on a frictionless horizontal ice surface. The boy maks a jump with a velocity component 5m/s in a horizontal direction with respect to the ice. With what velocity does the board recoil? with what rate are the boy and the board seperating from each other?

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Verified by Experts

The correct Answer is:
A, B, C, D
`p_i=p_f`
`: 0=(25)(5)+(10)(v)`
or `v=-12.5m//s`
Negative sign implies that this velocity is opposite to the direction of velocity of boy. Two velocities are in opposite directions.
Hence, `|v_r|=`Magnitude of relative velocity
`=12.5+5.0=17.5m//s`
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