1. Section 3 – pg 350 Acceleration
Chapter 9
Section 3 – pg 350
Acceleration

2. Pg 350
Changing Velocity
Acceleration: the rate at which velocity changes with time
Acceleration refers to increasing speed, decreasing speed, or changing direction

3. Increasing and Decreasing Speed
Pg 351
Increasing and Decreasing Speed
Whenever an object’s speed increases, the object accelerates
When an object slows down it is called deceleration or negative acceleration

4. Pg 351
Changing Direction
Acceleration may be due to changes in speed, direction, or both
A object that is spinning at a constant speed is accelerating because it is constantly changing direction

6. Calculating Acceleration
Pg 352
Calculating Acceleration
If an object is not changing direction, you can describe its acceleration as the rate at which its speed changes
To determine the acceleration of an object, you must calculate its change in velocity per unit of time
Acceleration = Final velocity – Initial velocity
Time

7. Graphing Acceleration
Pg 354
Graphing Acceleration
You can use both a speed-vs-time graph and a distance-vs-time graph to analyze the motion of an accelerating object

8. Speed-vs-Time Graph Pg 354
Constant slope means a constant acceleration
No slope means a constant velocity and no acceleration

9. Distance-vs-Time Graph
Pg 355
Distance-vs-Time Graph
A curved line on a distance-vs-time graph shows acceleration because velocity is not constant

10. Chapter 9 Section 3 Homework – pg 355

11. 1A. What are the three ways that an object can accelerate?

12. 1B. Describe how a baseball player accelerates as he runs around the bases after hitting a home run.

13. 1C. An ice skater glides around a rink at a constant speed of 2 m/s
1C. An ice skater glides around a rink at a constant speed of 2 m/s. Is the skater accelerating? Explain your answer.

14. 2A. What formula do you use to calculate the acceleration of an object moving in a straight line?

15. 2B. The velocity of a cyclist moving in a straight line changes from 0 m/s to 15 m/s in 10 seconds. What is the cyclist’s acceleration?

16. 3A. What types of graphs can you use to analyze the acceleration of an object?

17. 3B. Describe the motion of an object if its speed-vs-time graph is a horizontal line

18. 3C. What would a distance-vs-time graph look like for the moving object in part (b)?