Introduction

Newton's Third Law says that for every action there is an equal and opposite reaction. This means that if I push on the wall with 30N of force, the wall must push back on me, in the exact opposite direction, with exactly 30N. We call these two forces Force Pairs. We identify force pairs with a Free-body Diagram, which is one of the most important tools for solving many force problems.  

 

Newton's laws

 
Book on a scale on the Earth, FBD's and the 3rd law
 
 
Notes and clicker questions
 
 
 

Key Terms


Text/Videos

Here is a concise definition of Newton's Third Law;

 

This a comprehensive introduction to Newton's third law. This online textbook discusses Newton's third law with diagrams, worked problem examples, and interactive conceptual questions. All notation in this text is consistent with KC's.


Simulations

This first interactive game will challenge you with a few questions after a bout of Third Law tug-of-war with a cart;

 


Newton's Laws Of Motion (3): Action And Reaction


Additional Studying/Review