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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 tehboy and theboard separting from each other?

Text Solution

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Consider the board boy as a system. The exterN/Al forces on this system are a. weight of the system and b. normal contact force by the ice surface. Both these force are vertical and there is no exterN/Al force in horizontal directio. The horizontal component of linear momentum of the board+boy system is therefore constant.
If the board redcoils at a speed v
`0=(25kg)xx(5m/s)-(10kg)v`
or, `v=12.5m/s`
The boy and the board are separating wilth a rate
`5m/s+12.5m/s=17.5m/s`
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