Newton's Third Law of Motion

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Questions and Answers

What is the fundamental principle behind Newton's third law of motion?

For every action, there is an equal and opposite reaction (correct)

Every action has a lesser opposite reaction

Every action has a greater opposite reaction

Every action has no opposite reaction

What is another name for Newton's third law of motion?

The action-reaction law (correct)

The force-motion law

The motion-reaction law

The equal-opposite law

What is the relationship between the action force and reaction force in Newton's third law of motion?

The action force is always greater than the reaction force

The action force is always less than the reaction force

The action force is always equal to the reaction force (correct)

The action force is always opposite to the reaction force

Why do the action and reaction forces not cancel each other out?

Because the forces act on different objects Signup and view all the answers

What would happen if the equal and opposite forces were exerted on the same object?

The forces would cancel each other out Signup and view all the answers

What is the example of Newton's third law of motion mentioned in the passage?

A rowboat moving through the water Signup and view all the answers

What is the role of the person in the rowboat in the example of Newton's third law of motion?

The person exerts a force only on the water Signup and view all the answers

What is necessary for the cancellation of motion to occur?

The action force and reaction force are acting on the same object. Signup and view all the answers

What happens when the person in the rowboat exerts force on the water?

The person and the boat move forward due to the reaction force. Signup and view all the answers

Why does the rowboat move forward in the water but not on land?

The water has more mass than the cup of water on the land. Signup and view all the answers

How do rocket ships and fighter jets operate?

By using both action and reaction forces. Signup and view all the answers

What is the result of the action force of the engine and tires spinning on the ground?

The car moves forward. Signup and view all the answers

What is an example of the application of Newton's third law of motion besides rocket ships?

A water mill generating electricity. Signup and view all the answers

What is the purpose of the induction generator in a water mill?

To convert motion into electricity. Signup and view all the answers

Why does a person move forward when walking?

Because the person's muscles create an action force that the feet exert on the ground, and the reaction force of the ground is exerted on the person's body. Signup and view all the answers

Study Notes

Newton's Third Law of Motion

States that for every action, there is an equal and opposite reaction
When one object exerts a force on a second object, the second object exerts a force on the first that is equal but opposite in direction

Examples of Newton's Third Law

Rowboat: person exerts a force on the water using a paddle, and the water exerts a force on the rowboat and person
Rocket ships: combustion of fuel creates an action force on the expanding gases, and the expanding gases exert an equal reaction force on the rocket ship
Fighter jets: engine exerts an action force on the air, and the air exerts an equal reaction force on the fighter jet
Cars: engine and tires exert an action force on the ground, and the ground exerts an equal reaction force on the car
Bicycles: pedaling exerts an action force on the ground, and the ground exerts an equal reaction force on the bicycle
Walking: muscles exert an action force on the ground, and the ground exerts an equal reaction force on the body

Key Points

Action and reaction forces act on different objects
Forces do not cancel each other out because they act on different objects
If action and reaction forces act on the same object, they will cancel each other out