1. Newton’s Third Law of Motion

2. Newton’s Third Law of Motion (copy)
If object A exerts a force on object B, then object B exerts a force equal in size, but opposite in direction
For every action force, there is a reaction force equal in magnitude but opposite in direction

3. (copy) – add to note
The action and reaction forces act on different objects
***since the action and reaction forces are acting on different objects, they will appear on separate FBDs

4. Practice/Examples
1. Describe the reaction force for each of the following forces
A) the southward force of a field goal kicker’s toe on a football
the northward force of the football on the kicker\s toe
B) the backward force of a jogger’s shoe on the ground
C) the downward force of a book on a desk
The forward force of the fground on the jogger\s shoe
The upward force of the desk on the book

5. 2. Two skates are standing on ice facing each other
2. Two skates are standing on ice facing each other. Skater 1 pushes on skater 2 with a force of 70 N[E]. No friction acts on either skater. The mass of skater 1 is 50 kg and the mass of skater 2 is 70 kg.
A) state the action and reaction forces
B) state what will happen to each skater
C) Draw the FBD of each skater
D) calculate the acceleration of each skater

6. Practice Worksheet (questions #1-4)
Questions on page 141, #4, 5, 6, 7, 9
Time for a QUIZ (Forces and Newton’s Laws)
 try the practice one on my website