Question

The Earth moves around the sun in a nearly circular path, how much work is done by the gravity of the sun.

Answer 1

1. Work is said to be done if we applied a force on an object and the object moves to a distance.
2. So work done$W=F.s\cos \theta$, where F is the applied force, s is the displacement in the direction of the force.
3. And $\theta$ is the angle between force and displacement.
4. In the case of uniform circular motion $\theta$ is always${90}^0$.
5. $Cos\theta =0$,$andW=0$

Hence, no work is done when Earth moves around the sun.