If mass of earth is M, radius is R and gravitational constant is G, then work done to take 1 kg mass from earth surface to infinity will be

Potential energy of the 1 kg mass which is placed at the earth surface =−GMRits potential energy at infinite = 0∴Work done = change in potential energy =Uf-Ui=0--GmMR=GmMR=G(1)MR==GMR