7) When a body moves in a circular path, How much work in done by the body? Give Reason.
8) A Satellite revolves around the earth in a circular orbit. What is the work done by the satellite ? Give reason.
9) State whether work is done or not by writing yes or no, in the following cases ?
(a) A man pushes a wall.
(b) A coolie stands with a box on his head for 15 min.
(c) A boy climbs up 20 stairs.
10) A Coolie X carrying a load on his head climbs up a slope and another coolie Y carrying the identical load on his head moves the same distance on a frictionless horizontal platform. Who does more work ? Explain the reason.