When a body id lifted from surface of earth height equal to radius of earth, then the change in its potential energy is

Options

A. mgR
B. `(mgR)/(2)`
C. 2mgR
D. `(3)/(2)mgR`

Answer

b

Explanation

`"P.E."_(2)-"P.E."_(1)=-(GMm)/(r_(2))+(GMm)/(r_(1))`
`=GMm(-(1)/(2R)+(1)/(R))`
`=(gR^(2)m)/(2R)=("gRm")/(2)`