1. 1 1.Name the two forces that work together to keep the Earth and the moon in orbit with one another. Lesson Essential Question: How do gravity and inertia determine the orbits of solar bodies?

2. 2 Go over Bellringer Pass back graded papers Define and act out force Read and discuss the two factors that work together to keep the Earth and Moon in orbit with one another. Complete the Gravity and Inertia graphic organizer

3. Force A push or a pull exerted on an object.

4. Bill Nye Gravity YouTube What is Gravity Bill Nye Gravity Rap Gravity The attractive force between two objects.

5. Law of Universal Gravitation The scientific law that states that every object in the universe attracts every other object.

6. Gravity The strength of the force of gravity between two objects depends on two factors: the masses of the objects and the distance between them.

7. Mass – the amount of matter in an object (doesn't change depending on location) Weight – the force of gravity on an object (can change depending on location)

8. Gravity The strength of the force of gravity between two objects depends on two factors: the masses of the objects and the distance between them.

9. Gravity Versus Distance As a rocket leaves a planet’s surface, the force of gravity between the rocket and the planet changes. Use the graph to answer the following questions.

10. Question: What two variables are being graphed? In what units is each variable measured? Answer: Force of gravity on the rocket in millions of newtons and distance from the planet’s center in planetary radii

11. Question: What is the force of gravity on the rocket at the planet’s surface? Answer: Four million newtons

12. Question: What is the force of gravity on the rocket at a distance of two units (twice the planet’s radius from its center)? Answer: One million newtons

14. Inertia The resistance of an object to a change in motion.

15. Newton’s First Law of Motion An object at rest will stay at rest and an object in motion will stay in motion with a constant speed and direction unless acted on by force

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18. 18 Gravity and Inertia Newton concluded that two factors – GRAVITY and INTRTIA – combine to keep the moon in orbit around Earth. Gravity & Inertia Video

19. 19 Friday, November 20, 2015 Quiz Tuesday on Earth’s Movement. Study guide in Ebackpack.

20. 1.Cards will be distributed to individuals or pairs. One student will read their card, staring with the prompt “Who has….” The student who has the matching vocabulary word will stand up and respond “I have…Who has…”