Question

A satellite revolves around a planet in a circular orbit. What is the work done by the satellite at any instant? Give a reason

Answer 1

The work done is zero because the centripetal force on the body at any instant is directed towards the centre of the circular path and the displacement at that instant is along the tangent to the circular path, i.e., normal to the direction of force on the body. Since, θ = 90° , cos 90° = 0. Therefore, work done is zero.