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Calculate the work done and energy spent...

Calculate the work done and energy spent in the following two cases .
(a) Smitha has been reading a book since 1 hour .
(b) A child is pushing a car and the car's displacement is zero.

Text Solution

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The correct Answer is:
(a) zero, (b) zero
(a) Reading is a kind of mental work, so physical work done by Smitha in reading a book is zero, therefore, mechanical energy spent on it is also zero.
(b) A child cannot displace a car with his push, so there is no displacement. Therefore, work done and energy spent are zero.
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