Newton’s third law of motion
Newton’s Third law of motion
Newton’s third law of motion deals with the reaction of a body when a force acts on it.Let a body A exerts a force on another body B ,the body B reacts against this force and exerts a force on body A.The force exerted by body A on B is the action force whereas the force exerted by body B on A is called the reaction force.Newton’s third law of motion states that:
“To every action there is always an equal but opposite reaction.”
According to this law,action is always accompanied by a reaction force and the two forces must always be equal and opposite.Note that action and reaction forces act on different bodies.
What are examples of third law of motion?
Consider the books lying on a table as shown in figure.The weight of the books is acting on the table in the downward direction.This is the action,The reaction of the table acts on the books in the upward direction.
Consider another example.Take an air filled balloon is set free,the air inside it rushes out and the balloon moves forward.In this example,the action is by the balloon that pushes the air out of it when set free.The reaction of the air which escapes out from the balloon acts on the balloon forward.A rocket moves on the same principle.When its fuel burns,hot gases escape out from its tail with a very high speed.The reaction of these gases on the rocket causes it to move opposite to the gases rushing out of its tail.