Posted by bobby on Tuesday, January 4, 2011 at 7:14pm.
WEll, figure the force from any corner. That same magnitude force acts at the other corner, 90 degrees, which when added to the force from the first corner, gives a force of sqrt2 * magnitude of the original force (prove that), along the diagonal direction. Finally, add that to the froce from the opposite corner, (1/2 the first force), in the same direction, so you should get first force *(.5+sqrt2) as the net force, along the direction of the diagonal. YOu should do all the math to prove this.