The gravitational potential energy of a body of mass ‘ m ’ at the earth’s surface `-mgR_(e)`. Its gravitational potential energy at a height `R_(e)` from the earth’s surface will be (Here `R_(e)` is the radius of the earth)

Options

A. `-2mgR_(e)`
B. `2mgR_(e)`
C. `1/2mgR_(e)`
D. `-1/2mgR_(e)`

Answer

D

Explanation

`DeltaU=u_(2)-u_(1)=(mgh)/(1+h/(R_(e)))=(mgR_(e))/2`
`U_(2)=u_(1)+(mgR_(e))/2=-mgR_(e)+(mgR_(e))/2=-(mgR_(e))/2`