Lesson: Newton’s Third Law of Motion High School Physics

Physics

In this lesson, we will learn how to apply Newton’s third law of motion to analyze systems of forces.

Video

16:00

Sample Question Videos

08:46
08:47
05:30

Worksheet

Q1:

Which of the following statements most correctly describes Newton’s third law of motion?

Q2:

A stone of mass 686 g is thrown vertically upward from Earth with a force of 45 N.

What magnitude force does the gravitational field of Earth exert on the stone?

What magnitude force does the gravitational field of the stone exert on Earth?

Which of the following statements most correctly describes the motion of Earth due to the gravitational field of the stone?

What magnitude force does the stone exert on the person who throws it?

Q3:

A block has a mass of 500 g. The block is part of a system of objects. One end of the block is attached to a string and the other end of the string is attached to a ball by passing over a pulley, as shown in the diagram. The ball is inside a box that also contains a spring. A hole in a wall of the box allows the string to enter the box, pass through the gap in the center of the spring, and connect to the ball. All the objects in the system are at rest.

How much force does the block apply to the string?

How much force does the string apply to the ball?

How much force does the ball apply to the spring?

How much force does the spring apply to the ball?

How much force does the ball apply to the string?

How much force does the string apply to the block?

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