1. Newton’s 3rd Law of Motion
For every action

2. If object A applies a force, F, on object B then object B applies a force, - F, on object A. The forces are equal but in opposite directions. FBonA FAonB A B

3. Derek Jeter swings a bat. The bat applies a force of 300N on the ball
Derek Jeter swings a bat. The bat applies a force of 300N on the ball. Which of the following is true?
The bat applies more force on the ball than the ball applies on the bat.
The ball applies more force on the bat than the bat applies on the ball.
The bat applies the same force as the ball applies on the bat.

4. For years, space travel was believed to be impossible because there was nothing which rockets could push off of in space in order to provide the propulsion necessary to accelerate. This inability of a rocket to provide propulsion is because ...
a. ... space is void of air so the rockets have nothing to push off of.
b. ... gravity is absent in space.
c. ... space is void of air and so there is no air resistance in space.
d. ... nonsense! Rockets do accelerate in space and have been able to do so for a long time.

6. Many people are familiar with the fact that a rifle recoils when fired
Many people are familiar with the fact that a rifle recoils when fired. This recoil is the result of action-reaction force pairs. A gunpowder explosion creates hot gases which expand outward allowing the rifle to push forward on the bullet. Consistent with Newton's third law of motion, the bullet pushes backwards upon the rifle. The acceleration of the recoiling rifle is ...
a. greater than the acceleration of the bullet.
b. smaller than the acceleration of the bullet.
c. the same size as the acceleration of the bullet.

7. They apply the same force on each other
They apply the same force on each other. F = ma F = ma Smaller masses (bullet) have a greater acceleration. Larger masses (rifle) have a smaller acceleration.

8. Why doesn’t the same thing happen to the car?
Action: Girl pushes on car. Reaction: Car pushes on girl. If she pushes the car what will happen to her?
Why doesn’t the same thing happen to the car?

9. Action: Earth pulls down on man Reaction: Man pulls up on Earth
If he jumps up into the air what happens to him? What happens to Earth? Why? I thought the forces were equal!