Summary
Highlights
Newton's Third Law states: 'For every action, there is an equal and opposite reaction.' This means that in every interaction, there is a pair of forces acting on two interacting objects. The size of the forces on the first object equals the size of the force on the second object, but in the opposite direction. Forces always come in equal and opposite action-reaction pairs.
The video provides examples: a girl sitting on a chair exerts a downward force, and the chair exerts an equal upward force. Birds fly by pushing air downwards (action), and the air pushes the bird upwards (reaction). When dribbling a ball, the hand pushes the ball down, and the ground pushes the ball up with an equal and opposite force, making it bounce.
In summary, when a body exerts a force on another, an equal amount of force is always exerted back on it. This principle is fundamental to Newton's Third Law of Motion or the Law of Interaction.
Even when sitting or standing, you are exerting force. When sitting, your body exerts a downward force on the chair, and the chair exerts an upward force on your body. These are called action and reaction forces, the subject of Newton's Third Law of Motion.