1. Acceleration Physics 1 Dimensional Motion Chapter 2 Section 2 – pages 48-58

2. Acceleration Acceleration (a) – the rate of change of velocity in a given time interval Acceleration (a) – the rate of change of velocity in a given time interval - units = m/s 2 - units = m/s 2 - Equation a avg = change in velocity = Δ V = v f – v i a avg = change in velocity = Δ V = v f – v i change in time Δt t f - t i change in time Δt t f - t i

3. Acceleration has magnitude and direction  Can be positive or negative ***A negative value for acceleration does not always mean something is slowing down!

4. Acceleration has magnitude and direction - Examples: (Table 2-3 page 51) - Speeding up in a positive direction = +a - Slowing down in a positive direction = -a - Speeding up in a negative direction = -a - Slowing down in a negative direction = +a - Constant velocity in positive or negative direction  a = 0 m/s 2 direction  a = 0 m/s 2

5. Motion with constant acceleration Object speeds up or slows down at a uniform rate Object speeds up or slows down at a uniform rate

6. Equations There are 4 motion (kinematic) equations There are 4 motion (kinematic) equations Δx = ½ (V i + V f ) Δt V f = V i + a Δt Δx = V i Δt + ½ a (Δt) 2 V f 2 = V i 2 + 2a Δx V f 2 = V i 2 + 2a Δx

7. Constant Acceleration

8. Increasing Acceleration

9. Acceleration Comparison

10. Negative Velocity and Positive Acceleration

11. Positive Velocity and Positive Acceleration

12. Positive Velocity and Negative Acceleration

13. Negative Velocity and Negative Acceleration

14. Graphing A. Velocity vs. time graph  page 52 figure 2-11 B. Concept challenge page 50

15. Homework / In class work: p. 49 #1, 4, 5 p. 53 #1, 3, 4 p. 55 #1, 3, 4 p. 58 #3, 4, 5