1. 3rd Law Notes

2. 3rd Law
Newton’s 3rd Law of Motion states: if one object exerts a force on another object, then the second object exerts a force of equal strength in the opposite direction on the first object.

3. Another way to say the same law is to say, “for every action there is an equal but opposite reaction.”
Also said:

4. Action-Reaction Pairs occur when objects exert a force on one another.
Example 1: Jumping on the ground.
Action:
Reaction:
Action-Reaction

5. Action-Reaction Example 2: Kayaker paddling in the water Action:
Example 3: Person playing volleyball
Action-Reaction

6. Explain two people in roller blades pushing on one another:
Roller-Skating

7. You can not always detect motion when paired forces are in action.
Example 1: Earth’s gravity vs. object
Example 2: Dropping pencil on the ground
Detection

8. Action-Reaction Forces
The action-reaction forces do not cancel out because they are acting on different objects.
Action-reaction forces are different from two forces acting on the same object in opposite directions because action-reaction forces cannot cancel but forces on the same object from opposite directions can cancel.
Action-Reaction Forces

9. Momentum is always conserved!

10. 2 moving objects

11. 1 moving object

12. 2 connected objects