Problem: A uniform sphere with mass 64.8 kg is held with its center at the origin, and a second uniform sphere with mass 81.6 kg is held with its center at the point x = 0, y = 3 m.

Part I: What are the magnitude and direction of the net gravitational force due to these objects on a third uniform sphere with mass 0.485 kg placed at the point x = 4 m, y = 0?

Part II: Where, other than infinitely far away, could the third sphere be placed such that the net gravitational force acting on it from the other two spheres is equal to zero?

I want you to clarify the physics in this above problem.