For every force exerted by object A on object B, an equal and opposing force is exerted by object B on object A. I need help understanding the principle. I understand it when dealing with a completely stationary object: pushing on a solid wall, it exerts an equal force back to your hand, resulting in no net movement. But what about when I push something and move it? It seems to me that the force of my hand is greater than the force of the pushed object, since it "gives" under the force and moves. How are the two forces equal?