Question

What is the work done by the moon when it revolves around the earth?

Answer 1

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) $=F\times d\times \cos \theta$

where F = applied force

d = displacement of the body

$\theta$ = angle between the applied force and the displacement of the body

In the case of revolution of moon around the earth, $\theta$ is $90°$. Thus, $W=F\times d\times \cos 90°$

= $F\times d\times 0=0$

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