Physics Problem 6.9
posted by Michael Moskvich .
Four 8.5 kg spheres are located at the corners of a square of side 0.56 m Calculate the magnitude and direction of the gravitational force on one sphere due to the other three?

Perform a vector addition of the three forces. The resultant will be an attraction along a diagonal to the opposite corner. The components perpendicular to the diagonal, due to the two masses at adjacent corners, will cancel out.