posted by Anonymous .
Four 7.5 kg spheres are located at the corners of a square of side 0.74 m. Calculate the magnitude and direction of the gravitational force on one sphere due to the other three.
Use symettry. YOu know the force will be diagonal.
the side components will be
and the diagonal will be
i got 1.71E-8 and that was wrong and then i got 1.03E-8 and it was still wrong
with sig figs the answer should be
2.0*10^-8 N towards the center of the circle