1. Newton’s Third Law of Motion

2. Warm up
State Newton’s first law of motion. State Newton’s second law of motion. Which one, force or mass, is directly proportional to acceleration. When the forces are balanced, do we have acceleration?

3. Newton’s Third Law of Motion
KEY CONCEPTS
WHAT IS NEWTON’S THIRD LAW OF MOTION?
WHAT IS AN ACTION AND REACTION FORCE?
DESCRIBE HOW FORCES COME IN PAIRS.

4. Try to push the corner of your table with the palm of your hand.
Introduction
Try to push the corner of your table with the palm of your hand.
What do you notice.

5. Introduction
Read the procedure of the activity and do your demonstration and then record your observations by filling in the designated part on the activity sheet

6. Newton’s Third Law of Motion
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 “For every action there is an equal but opposite reaction”

7. Action – Reaction Pairs
Kayak paddle pushes the water back, the water pushes the kayak forward
A dog pushes down on the ground, the ground pushes up on the dog causing it to leap into the air
Other Examples…….

9. Do Action – Reaction Forces Cancel?
If 2 equal act in opposite directions they are balanced and cancel each other out. There is no movement
Action – Reaction forces do not cancel out because they are acting on 2 different objects

10. Indicate which one is an action and which one is a reaction force

15. Wrap up
Newton’s Third law states that for every action force there is an opposite and equal reaction force.
Action and reaction force don’t cancel each other, since they are applied on different objects.
Forces occur in pairs.

16. Homework:
Section review questions #:
Quiz on Monday, Nov. 28, 2011
1- Gravity
2-Third Law of motion