1. The problem statement, all variables and given/known data Find an expression for the ratio g(r)/g(RE) of the magnitude of the gravitational acceleration at a distance r from the centre of the Earth to that at the surface of the Earth, for r > RE, i.e. for points above the surface of the Earth. 2. Relevant equations F(grav) = -Gm1m2 / r^2 3. The attempt at a solution I was thinking about making r the subject of the equation and hence becoming R(E) and then substituting into the original equation but it doesn't seem to show anything. I've been looking at this for a while but nothing is clicking any pointers would be very much appreciated as always.