Newton’s third law of motion describes how objects interact with each other when a force is applied.

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Look at this Newton's Cradle.​

Remember!

• Forces occur in pairs.

• Forces come in equal strength.​

• Forces come in opposite directions.

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Action Force - the force acting on an object that causes the reaction force​

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Reaction Force - ​the force that acts in the opposite direction to the action force

The ball strikes the ground PUSHES DOWN on the ground with a certain force.

Action Force

The ground PUSHES BACK UP on the ball with an equal force in the opposite direction. This causes the ball to move away from the ground.

Reaction Force