1. Gravity
Chapter 12
Section 2

2. Weight & Mass Weight is equal to the force of gravity on an object.
Weight is comparative to mass.
Equation for weight:
W=MG
W = weight
M = mass
G = free-fall acceleration (9.8 m/s2 on Earth)

3. Weight & Mass Free-fall acceleration is different on other planets!
This is because of the different masses of the planets.

4. Law of Universal Gravitation
All objects are attracted to one another due to gravity.
This is why objects fall.

5. Free Fall
Disregarding air resistance, all objects accelerate at the same rate.
Mass doesn’t matter!

6. Free Fall
On the Apollo 15 mission, astronaut David Scott released a hammer and a feather on the moon at the same moment. What happened?

7. Free Fall
When air resistance and weight are equal acceleration stops and reaches a maximum velocity called terminal velocity.

8. Projectile Motion Projectile Motion has two parts: Forms a curved path
Horizontal velocity
Vertical velocity
Forms a curved path

9. Review
Why would your weight be less on the moon than on Earth even though your mass does not change?

10. Review
How is weight different than mass?

11. Review
Why don’t you feel a gravitational force between you and your desk?

12. Review
What causes a thrown ball to follow a curved path?