Question

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:-

1.at the highest position of the body
2.at the Instant just before the body hits the earth
3.it remains constant all through
4.at the Instant just after the body is projected
please explain all the options ( the answer and also explain all the other options as to why they are wrong) ​

Answer 1

Answer:

4) At the instant just after the body is projected

Explanation:

We know g=GM/R²

Where R² is the distance between the body and the centre of the earth

So as R increases, g or the force on the body decreases.

As a result the body experiences most force when it is closest to the earth.