A satellite of mass “m” is in a circular orbit of radius 1.5R around the earth of radius R. How much energy is required to move it to an orbit of radius 2R?

Correct Answer: -(G*M*m)/12R
Total energy at 1.5R (TE) = - Total energy at 2R (TE’) = - The difference in energy is the required energy. Difference = TE’ – TE = - – ] = - + (G*M*m)/3R] = (G*M*m)/12R.