Answers

2016-02-14T15:27:51+05:30
As the body is perpendicular to the surface , work done is zero
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2016-02-14T19:54:07+05:30
If he is starting from rest:
work done=change in kinetic energy=1/2m (v square- u square)
=30 (5×5-0×0)= 30×25=750j
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