Action Physical

Action (Physical). The action of one body on another, as understood by Newton in his third law of motion, is simply the force that the one impresses on the other. This law is that action and reaction are equal and opposite, or that the mutual actions of any two bodies are always equal and oppositely directed. Thus, if one body presses another, it is also pressed with the same force in the opposite direction; if one body exerts an attractive force on another, it also is attracted with an equal force.