How can the function for distance over time be found for an object which is thrown away from Earth? Acceleration as a function of distance is g = GM/r^2, where GM is constant, so let c = GM, then g = c/r^2. Then I wondered, maybe the formula for distance can be found by solving the differential equation r'' = c/r^2? I have never studied differential equations, so I have no idea about it, even to whether I can really say r'' = c/r^2. If someone can elucidate my mind, I shall be grateful.