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A man, sitting firmly over a rotating st...

A man, sitting firmly over a rotating stool has his arms streched. If he folds his arms, the work done by the man is.

A

zero

B

positive

C

negative

D

may be positive or negative

Text Solution

Verified by Experts

The correct Answer is:
B
`KE = (L^(2))/(2I)` since by folding arm moment of inertia decreases while angular momentum remain constant. So `KE` will increases therefore work done by the man is positive.
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