Question

Moon revolves around the earth due to gravitational force (F) of earth on moon.
The work done by the gravitational force is (r=radius of circular orbit of moon).
(b) F.gr
(d) negative work
(a) F.2tr
(c) Zero​

Answer 1

Explanation:

The moon is revolving around the earth. In this process, the work done by the gravitational force is zero because the displacement of the moon is at right angle to the gravitational force.

Answer 2

Answer:

Zero..

Explanation:

The work done by the moon when it revolves around the earth is zero because here displacement of moon and gravitational force of earth are perpendicular to each other.

i.e., Work done (W) =F×d×cosθ

i.e., Work done (W) =F×d×cosθwhere F = applied force

i.e., Work done (W) =F×d×cosθwhere F = applied forced = displacement of the body

i.e., Work done (W) =F×d×cosθwhere F = applied forced = displacement of the bodyθ = angle between the applied force and the displacement of the body

In the case of revolution of moon around the earth, θ is 90°. Thus, W=F×d×cos90°

In the case of revolution of moon around the earth, θ is 90°. Thus, W=F×d×cos90° = F×d×0=0

So, the work done by the moon when it revolves around the earth is zero.