A body of mass m is situated at a distance 4R_e above the earth’s surface, where R_e is the radius of earth. How much minimum energy be given to the body so that it may escape : 

mgR_e/5

Potential energy of the body at a distance 4R_e from the surface of earth :

\(U = - \frac{mgR_e}{1 + \frac{h}{R_e}}\)

\(U = - \frac{mgR_e}{1 + 4}\)

\(U = - \frac{mgR_e}{5}\) ... [As h = 4R_e : given]

So minimum energy required to escape the body will be mgRe/5.