# ICSE Class 10 Answered

**pls derive mgh in physics**

The term ' m g h ' is gravitational potential energy of mass m at a height h above earth surface or above some reference level.

Gravitational potential energy U(r) of a mass m is

where G is universal gravitational constant , M is mass of earth and r is distance of mass m from center of earth.

Gravitational potential energy U(R) of a mass m on earth surface is

............................ (1)

Gravitational potential energy U(R+h) of a mass m at a height h above earth surface is

If we take earth's surface as reference , then potential energy of mass m at a height h above earth surface is

By neglecting (h/R)^{2} and higher powers , we get

where ( G M )/R^{2} is acceleration due to gravity g on earth surface .

hence potential energy of mass m at a height h above earth surface = m g h .