Suppose the moon has a radius of r miles and a payload weighs p pounds at the surface of the moon (at a distance of r miles from the center of the moon). when the payload is x miles from the center of the moon (x ≥ r), the force required to overcome the gravitational attraction between the moon and the payload is given by the following relation: required force = f(x) = r2p x2 pounds for example, the amount of work done raising the payload from the surface of the moon (i. e., x = r) to an altitude of r miles above the surface of the moon (i. e., x = 2r) is work = b f(x) dx a = 2r r2p x2 dx r = rp 2 mile-pounds how much work would be needed to raise the payload from the surface of the moon (i. e., x = r) to the "end of the universe"?