Question

Three masses are aligned along the x axis of a rectangular coordinate system so that a 2 kg mass is at the origin, a 3kg is at (2,0) m, and a 4 kg mass is at (4,0) m. Find (a) the gravitational force exerted on the 4 kg mass by the other two masses and (b) the magnitude and direction of the gravitational exerted on the 3 kg mass by the other two. (answer: 2.33x10^-3N, 1x10^-10N)