1. What keeps the Earth and moon in orbit?

2. In 1666, Isaac Newton realized that a force is responsible for making objects fall.

3. Force
A push or pull on an object.

4. GRAVITY Is a force Attracts all objects to each other
Measured in units called newtons.
Strength depends on the mass of the objects and the distance between them.

5. If the distance increases, the force of gravity decreases.
If the mass increases, the force of gravity increases
If the distance increases, the force of gravity decreases.

6. Mass is the amount of matter in an object.
Weight is the force of gravity on an object.
Unlike mass, which doesn’t change, an object’s weight can change depending on its location.

7. If the sun and Earth are constantly pulling on one another because of gravity, why doesn’t Earth crash into the sun?

8. Inertia The tendency of an object to resist a change in motion.
An object with greater inertia is more difficult to start or stop.

9. Can you use inertia to explain the motion in this picture?

10. NEWTON’S 1st LAW OF MOTION
“An object at rest will stay at rest unless acted on by a force.”
“An object in motion will stay in motion unless acted on by a force.”

11. Inertia!!!

12. Can use gravity and inertia to explain the motion that will take place on this ride?