Hi guys I need help with this after quite some time A piece of rock far out in space is relative to the earth. Under the influence of the earth's gravitational attraction, it begins to fall towards the earth along a straight adial line. With what speed will the rock hit the earth? (Given radius of earth = 6.4 x 10^6m) I couldn't find the radius of orbit of the rock. I suppose since it is at rest relative to earth it must have the same angular speed? How do I find the radius from here? I figured that its period is not the same as the earth's as the T^2 = k(r^3). Thanks a lot!