11.A body is raised to a height h so that the force of gravity on body is 1% of the value on the surface of Earth. If the radius of the Earth is 6400 km, then the value of h is

12.A research satellite of mass 200 kg circles the Earth in an orbit of average radius 3R/2, where R is the radius of the Earth. Assuming the gravitational pull on a mass 1 kg on Earth s surface to be 10 N, the pull on the satellite will be

13.At what height above the surface of Earth the value of g is the same as that in a mine 10 km deep ?

14.A mass m is raised from the surface of Earth to a point which is at a height nR from the surface of Earth. Change in potential energy is

15.A body weighs 63 N on the surface of the Earth. At a height h above the surface of Earth, its weight is 28 N while at a depth h below the surface of Earth, the weight is 31.5 N. The value of h is