[SOLVED] Weight in Terms of Distance From Earth 1. The problem statement, all variables and given/known data At what height above the earth's surface will an astronaut have a true weight that is one half his weight on earth? 2. Relevant equations F=G(m1*m2)/r^2 (GM)/(4*pi^2)=(R^3)/t^2 3. The attempt at a solution I did: F/2=(G*m1*m2)/r^2 r=sqrt((2*G*m1*m2)/F) My teacher got sqrt(2) times the radius of the earth. Where do I go from there?