1. The problem statement, all variables and given/known data Four 9.0 kg spheres are located at the corners of a square of side 0.72 m. Calculate the magnitude of the gravitational force on one sphere due to the other three. 2. Relevant equations Fg=G(M1)(M2)/r^2 3. The attempt at a solution I figured out the force the each of the two spheres perpendicular to the corner one by doing Fg=[(6.67e-11)(9)(9)]/[.72^2]=1.04e-8. then i used the pathageon theorum to find the radius to the sphere in the opposite corner of the square by doing square root of .72^2+.72^2=1.02. I am now having trouble finding the force of the two corner balls pulling at a 45 degree angle towards the middle of the square.