# Newton's third law of motion

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##### Intros
###### Lessons
1. Introduction to Newton's third law
2. What is Newton's third law?
3. Identifying forces in action-reaction force pair
##### Examples
###### Lessons
1. Understanding Newton's third law and free body diagrams

A rock sits on a table. Draw complete free body diagrams for the rock and the table and highlight the action-reaction pair that includes the rock pushing down on the table.

1. Calculations with Newton's second and third laws
1. An 85.0 kg fireman slides down a pole with an acceleration of 2.85 $m/s^{2}$. Find the action-reaction force pair that involves the pole and calculate these forces.
2. Two ice skaters stand on a frictionless ice rink and face each other, each holding the end of a rope. 50.0 kg skater A pulls on the rope, pulling 40.0 kg skater B with a force of 25.0 N.

i. Draw a free body diagram and find the acceleration of skater B.

ii. When skater A pulls on skater B, does skater A accelerate? If so, draw a free body diagram and calculate the acceleration.