A body projected vertically from the earth reaches a height equal… - Vidyadip

MCQ

A body projected vertically from the earth reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest

A
at the highest position of the body.
✓
at the instant just before the body hits the earth.
C
it remains constant all through
D
at the instant just after the body is projected.

✓

Answer

Correct option: B.

at the instant just before the body hits the earth.

b
Power, hitting $P= \vec F\cdot \vec v = 0 = Fv\cos\theta $
Just before hitting the earth $\theta =0^o$ Hence, the power exerted by the gravitational force is greatest at the instant just before the body hits the earth.

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