1. AIM: Describe the factors that effect the strength of gravity and how inertia differs from gravity? OBJ: Given notes, images and activity sheet SWBAT describe the factors that effect the strength of gravity and how inertia differs from gravity with 70% accuracy DN: HW check- Earth in Space Activity Sheet ACT: Introduction to Gravity and Inertia (notes) Complete Earth’s Motions Activity Sheet HW: Text, read 16-19, Complete Gravity & Motion Activity Sheet; Work on Astronomy Activity Sheet; Astronomy Exam, Dec 19. Weather & Climate (Red) Textbooks due Dec 18,19.

2. GRAVITY
Force: a push or pull Gravity: attractive force between objects containing mass [In reality, gravity is the warping of spacetime by objects in the universe]. Gravitational Force Unit: newton, N Two factors affect gravity: 1) mass of the object’s, 2) distance between objects. F(g) = M1 x M2_ d2

3. Gravity

4. Gravity

5. Mass
Mass: amount of matter (atoms) in an object Weight: force of gravity on an object’s mass. Weight = mass x gravity Note: object’s mass doesn’t change but object’s weight changes due to change in gravity because planets/moon vary in size.

6. Distance
Gravity decreases, as distance increases Gravity increases, as distance decreases Inverse relationship
gravity
distance

8. Inertia Inertia: tendency of an object to resist a change in motion.
Newton’s first law of motion:
Objects at rest, remain at rest
Objects in motion, remain in motion (at constant speed & direction) unless acted on by a force.

9. Inertia

10. Orbital Motion Orbit is due to two (2) factors: 1] gravity 2] inertia