Four 8.5 kg spheres are located at the corners of a square of side 0.52 m. calculate the magnitude and direction of the gravitational force exerted on one sphere by the other three. magnitude

3.4x10^-8 N of force directly towards the sphere in the opposite corner of the square. The gravitational attraction of two masses towards each other is F = G (m1m2/r^2) where G = gravitational constant m1, m2 = masses r = distance between the centers of the masses. So the force being exerted by the masses alone an edge of the square would be F = 6.674x10^-11 N (m/kg) ^2 * ((8.5 kg) ^2) / ((0.52m) ^2) F = 6.674x10^-11 N (m/kg) ^2 * (72.25 kg^2) / (0.2704 m^2) F = 6.674x10^-11 N (m/kg) ^2 * 267.1967 (kg/m) ^2 F = 1.78327x10^-8 N There are 2 masses that affect a mass on a corner so that the sum of their vectors will result in a 3rd vector aiming towards the mass in the diagonal corner. So sqrt (2 (1.78327x10^-8 N) ^2) = 2.52193x10^-8 N The mass in the diagonal corner will also be attracting. The distance to that mass is sqrt (2 * (0.52m) ^2) = 0.735391052 m F = 6.674x10^-11 N (m/kg) ^2 * ((8.5 kg) ^2) / (2 * (0.52m) ^2) F = 6.674x10^-11 N (m/kg) ^2 * (72.25 kg^2) / (0.5408 m^2) F = 6.674x10^-11 N (m/kg) ^2 * 133.5984 (kg/m) ^2 F = 8.916355x10^-9 N This vector will be along the same line as the combined vector from the other 2 masses, so they'll add directly. F = 8.916355x10^-9 N + 2.52193x10^-8 N = 3.4136x10^-8 N Since we have 2 significant figures in our data, the result rounded to 2 significant figures is 3.4x10^-8 N