1. Physics 31 Fall 2008

2. Information Homework Assignments made daily, but collected weekly on Wednesdays. Help session Tuesday evenings 6:00- 8:30pm Room 127

3. Motion diagrams Position and time Velocity Scientific notation and units Vectors and motion Chapter 1 Concepts of Motion and Mathematical Background Topics: Sample question: As this snowboarder moves in a graceful arc through the air, the direction of his motion, and the distance between each of his positions and the next, is constantly changing. What language should we use to describe this motion? Slide 1-1

4. Four Types of Motion We’ll Study Slide 1-10

5. Making a Motion Diagram Slide 1-11

6. Examples of Motion Diagrams Slide 1-12

7. A simplifying model in which we treat the object as if all its mass were concentrated at a single point. This model helps us concentrate on the overall motion of the object. The Particle Model Slide 1-13

8. The position of an object is located along a coordinate system. Position and Time At each time t, the object is at some particular position. We are free to choose the origin of time (i.e., when t = 0). Slide 1-14

9. Displacement The change in the position of an object as it moves from initial position x i to final position x f is its displacement ∆x = x f – x i. Slide 1-15

10. Speed Slide 1-22 The car moves 40 m in 1 s. Its speed is = 40. 40 m 1 s m s The bike moves 20 m in 1 s. Its speed is = 20. 20 m 1 s m s

11. Velocity Slide 1-23

12. Homework Due Wednesday –Read Chapter 1: 1-5 Motion, Scientific Notation, dimensions, vectors –Problems Ch. 1: CQ3, CQ4, CQ6, MC21, 3, 4

13. Help session tomorrow, Tuesday, August 26, room 127