A rocket of mass m is fired vertically from the surface of the earth, i.e., at r = r1. Ass...

A rocket of mass m is fired vertically from the surface of the earth, i.e., at r = r1. Assuming that no mass is lost as it travels upward, determine the work it must do against gravity to reach a distance r2. The force of gravity is F = GMem/r2 (Eq.13-1), where Me is the mass of the earth and r the distance between the rocket and the center of the earth.