Question

A planet is revolving round the sun in an elliptical orbit. The work done on the planet b the gravitational force of sun is zero.

• A. In some parts of the orbit
• B. In any part of the orbit
• C. In no part of the orbit
• D. In one complete revolution

Answer 1

Answer: (A), (D)

In some parts of the orbit
In one complete revolution

A particle is moving in elliptical orbit the work done will be zero at the moment when the displacement vector makes ${90}^0$ with acceleration as

And also in the whole cycle as net displacement becomes zero in a conservation force field.