Newton’s third law of motion

Definition

Newton's Third Law of Motion states that for every action, there is an equal and opposite reaction. This means that forces always come in pairs, acting on two interacting objects.

5 Must Know Facts For Your Next Test

1. The law implies that forces are mutual and occur simultaneously.
2. An example includes a swimmer pushing against water; the water pushes back with an equal force.
3. Action-reaction forces act on different objects, not on the same object.
4. The magnitude of both forces is always equal, but they are in opposite directions.
5. This law is fundamental in understanding the conservation of momentum.

Review Questions

• What does Newton's Third Law of Motion state about the relationship between forces?
• Provide an example illustrating Newton's Third Law of Motion.
• Explain why action-reaction force pairs do not cancel each other out.

Related terms

Force: A push or pull upon an object resulting from its interaction with another object.

Momentum: The quantity of motion an object has, which is dependent on mass and velocity.

Equilibrium: A state where all forces acting upon an object are balanced, resulting in no acceleration.