posted by Allison .
How much work is required to lift a 600-kg satellite to an altitude of 4 * 10^6 m above the surface of the earth? The gravitational force is F=GMm/r^2, where M is the mass of earth, m is the mass of the satellite, r is the distance between them. The radius of the earth is 6.4 * 10^6 m, its mass 6 *10^24 kg. And G = 6.67 *10^-11