The gravitational potential at a point at height h from the surface of earth is -6.50 xx 10^(7) J kg^(-1), and acceleration due to gravity is 7.2 m//s^(2). Calculate the value of h if radius of earth is 6400 km.

The gravitational potential at a point at height h from the surface of

1.	The gravitational potential at a point at height h from the surface of earth is -6.50 xx 10^(7) J kg^(-1), and acceleration due to gravity is 7.2 m//s^(2). Calculate the value of h if radius of earth is 6400 km.
Answer» 2,627 km 3,627 km 4,627 km 1,900 km Solution :(R + h) = DISTANCE from centre of earth `V = (-GM)/((R + h)) = -6.50 xx 10^(7) J kg^(-1)` …(i) `a = + (GM)/((R+h)^(2)) = 7.2 m//s^(2)` …(II) Dividing (i) by (ii) `(GM(R+h)^(2))/((R+h).GM) = (R+h) = (6.50 xx 10^(7))/(7.2) = 0.9027 xx 10^(7) m` (R +h) = 9,027 km Height of the point above earth surface `h = 9,027 km - 6,400 km` = 2,627 km