AP Physics C Unit 3 Work and Energy

The gravitational attraction between two objects with masses m1 and m2, separated by distance x, is F = Gm1m2/x^2, where G is the gravitational constant. a. How much work is done by gravity when the separation changes from x1 to x2? Assume x2 less than x1. b. If one mass is much greater than the other, the larger mass stays essentially at rest while the smaller mass moves toward it. Suppose a 1.5x10^13 kg comet is passing the orbit of Mars, heading straight for the sun at a speed of 3.5 x 10^4 m/s. What will its speed be when it crosses the orbit of Mercury?