Question

Assertion(A):A 40 Kg girl is running along acircular path of radius 1 m with a unifrm speed .The work done by the girl is zero.

Reason (R): In this case,displacement is zero after one complete rotation.

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Answer 1

Answer:

Both A and R are true but R doesn't satisfy A

Explanation:

actually in this case the angle b/w force and displacement is π/2 every time.

to have a uniform speed in a circular motion,the girl has to apply a force centripetally . so the angle b/w the centripetal force and displacement become 90°.

so , w=fs cos(π/2)

so,w=0

Answer 2

that one above is the ans mark him brainliest