1. The problem statement, all variables and given/known data Four spheres of equal 9.5 kg are located at the corners of a square of length 0.6 m per side. Find the magnitude and direction of the gravitational field on one by the other three spheres 2. Relevant equations gravity = GM/r^2 with G = gravitation constant, M = mass, r = radius The field strength of the diagonal mass = GM/(r*.71)^2 The sum of the field magnitudes from the two neighbored masses is GM(.71)/r^2 The total magnitude = GM/((2r)^2) + GM(.71)/r^2 3. The attempt at a solution So to clarify the ".71" is the sin of 45°, the radius of the neighboring spheres is .6 m and using phythagorean the diagonal radius is .85 m. Solving..... the answer in the book says....3.2 x 10^-8 N but.... (6.67x 10^-11)(9.5)/(2 * 0.6)^2 + (.71)(6.67x10^-11)(9.5)/(.85)^2= 4.4x10^-10 + 6.2x10^-10 = 1.06 x 10^-9 Where do I need to be set straight? Wrong equation(s) or substitutions?