Question

An object of mass, m, is loacted at a height, h above the earth's surface in a region where the gravitational field strength of the earth is g. Under what circumstance(s) can the expression U = mgh be used, to calculate its gravitational potential energy, U?

Answer 1

Answer

Gravitational Potential energy at hight h above the surface of earth is given by

$U=\frac{mgh}{1+\frac{h}{R}}$

If height of object is very less as compare to radius of earth

h<<<R

Then

Gravitational Potential energy can be given as

$U=mgh$