1. Unit 2 Inertia

2. Newton’s First Law of motion: Inertia Aristotle and motion: he divided motion into Natural motion (straight up or straight down and circular motion for the heavens) Their motion were not caused by forces. Violent motion-resulting from forces (push or pull) having an external cause. Copernicus reasoned that earth traveled around the sun but worked on his ideas secretly to escape persecution Galileo concluded that if it were not for friction an object in motion would keep moving forever. (read together p 26-27)

3. Force: any push or pull Friction: force that acts between materials that are moving past each other Newton’s Law of Inertia (First Law) YouTube - Eureka! Episode 1 - Inertia Building on Galileo’s idea, Newton restated: Every object continues in its state of rest, or of motion in a straight line at a constant speed, unless a force is exerted upon it. The Physics Classroom Multimedia Physics Studio Tablecloth trick YouTube - Tablecloth trick Robert Krampf on Sclipo: the social learning network If you can successfully perform the tablecloth trick for our next class using a large vase or plates and drinking glasses, you don’t have to take notes and quiz for that day, you will have those points.

4. Mass- a measure of inertia Mass (m): amount of material present in an object. Mass is a measure of inertia of an object. The more mass, the more force it takes to change its state of motion. What would you prefer to kick: an empty trash can or a trash can filled with rocks? Units: kilogram (kg) Mass is not weight Weight (W) is the force due to gravity upon a body. Units: Newton (N) Mass is the same in any location (Earth, the moon, etc) Weight varies with locations (depends on the gravitational force) Solar System, Solar System Information, Facts, News, Photos -- National Geographic Solar System, Solar System Information, Facts, News, Photos -- National Geographic

5. Weight = mass x acceleration due to gravity W = mg Now on, we will use the real value of g: 9.8m/s 2 The moving Earth: Earth travels at 30km/s Your are standing next to the wall and you decide to jump up. Does the 30km/h wall slam into you? Why not? A bird at rest on a branch sees a worm on the ground, drops down vertically and catches it. How is this possible? (read together p 33-34)

6. Sample Problems 1) Karina the ballet dancer has a mass of 45.0kg. a) What is Felicia’s weight on Earth? b) Her mass on Jupiter, where the acceleration due to gravity is 25.0 m/s? c) Her weight on Jupiter?

7. Sample Problems 2) Antonio has a weight of 800 N, what is his mass (in kg)?

8. Classwork Answer questions P 35 # 1-15 Problem solving practice: P 665 Chapter 4 #1,2, 5-8