Lesson: Newton’s Third Law of Motion Mathematics

In this lesson, we will learn how to solve problems on Newton’s third law.

Lesson Plan

Students will be able to

recall and state Newton’s third law of motion,
calculate reading on scales in an accelerating system,
find the acceleration of a system given the reading on a scale contained in the system,
combine all of Newton’s laws of motion.

Lesson Presentation

Lesson Video

Lesson Explainer

Lesson Worksheet

Q1:

An elevator is moving vertically upward at a constant speed. A man of mass 150 kg is standing inside. Determine the reaction force of the floor on the man. Take .

Q2:

Fill in the blank with , , , , or : When a body of mass is suspended from a spring scale fixed at the ceiling of an elevator and the elevator descends with uniform acceleration, then the apparent weight the real weight.

Q3:

An elevator is accelerating vertically upward at 2.6 m/s². A man of mass 124 kg is standing inside. Determine the reaction force of the floor on the man.