1. (8th) Chapter 12-2 Cornell Notes
Gravity and Motion

2. Chapter 12-2 Key Questions
What determines the strength of the force of gravity between two objects?
What two factors combine to keep the moon and Earth in orbit?

3. Chapter 12-2 Key Terms force- gravity- Universal Law of Gravitation-
mass-
weight-
inertia-
Newton’s 1st Law of Motion-
Chapter Key Terms

4. Chapter Paragraph 1
Isaac Newton: an apple falling reminded him of the moon’s orbit;
he realized a force acting between the earth and moon kept the moon in orbit.

5. Chapter Paragraph 2
Newton thought the force involved might be gravity;
he did not discover gravity but first to know that it happens everywhere;
Law of Universal Gravitation: every object in the universe attracts every other object.

6. Chapter 12-2 Paragraph 3 newton: unit based on strength of gravity;
depends on mass of objects and distance between them;
mass: amount of matter in an object;
pull of other objects not noticed because of their mass.

7. Earth exerts greater force because it’s so massive;
same force keeps moon in orbit;
weight: force of gravity on an object;
weight varies with location;
weight is 1/6 on the moon.
Chapter Paragraph 4

8. Chapter Paragraph 5
inertia: tendency of an object to resist a change in motion;
Newton’s 1st Law of Motion: object at rest stay at rest and/or object in motion stay in motion unless acted on by an outside force.

9. Chapter Paragraph 6
2 factors (inertia and gravity) keep Earth in orbit around the sun and the moon in orbit around the Earth;
inertia and gravity balance each other.