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An 80 kg man is riding on a 40 kg cart t...

An `80 kg` man is riding on a `40 kg` cart travelling at a speed of `2.5 m//s` on a frictionless horizontal plane jumps off the cart, such that, his velocity just after is zero with respect to ground. The work done by him on th esystem during his jump is given as `(A)/(4) KJ` (Ain integer). Find the value of A.

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The correct Answer is:
3
By conservation of linear momentum `(80 + 40) (2.5) = 80 (0) + 40 (v) rArr = v = 7.5 m//s`
work done `= DeltaKE = (1)/(2) 40 (7.5)^(2) - (1)/(2) (80 + 40) (2.5)^(2) = 750 J`
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ALLEN -CENTRE OF MASS-EXERCISE-V B
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