Nice and simple (for some) Center of Mass Calculator. The formula I used is: m1*x1+m2*x2+m3*x3+m4*x4+m5*x5 (and so on up to 9) x = ------------------------------------------------------ m1+m2+m3+m4+m5 (and so on up to 9) ============================================ m1*y1+m2*y2+m3*y3+m4*y4+m5*y5 (and so on up to 9) y = ------------------------------------------------------ m1+m2+m3+m4+m5 (and so on up to 9) Key: m1 = Mass of the first block m2= Mass of the second block (Either 1kg or 0kg) x1 = X position of the first block x2 = X position of the second block y1 = Y position of the first block y2 = Y position of the second block