1. Motion Ch 11

2. A. Motion 1. 2. Reference points are necessary and must be a stationary object.

3. B. Speed 1. The distance an object moves in a given amount of time. 2. Types of speed: a. Instantaneous – at a given moment b. Constant – Speed never change c. Average – 3. Speed = Distance / Time 4. Measured in units m/s

4. Example of Constant Speed While traveling on vacation, you measure the times and distances traveled. You travel 35km in 0.4 hour followed by 53km in 0.6 hour. What is your average speed? Speed = d t

5. Distance / Time Graphs Speed is graphed on a distance / time graph The slope of the line is the speed Constant speed will be a straight line Horizontal lines on a distance / time graph indicate the object has stopped. Acceleration will be a CURVE

6. Distance Time Graphs

7. C. Velocity 1. 2. Velocity can change due to speed, change in direction or both. Examples: Bike around a curve Roller Coaster

8. D. Acceleration 1. The rate of change of velocity 2. a = (vf – vi) / t 3. Units are m/s 2 4. 5. Free Fall – object accelerates due to gravity at 9.8m/s 2

9. Example: constant speed & acceleration

10. Example of acceleration A ball rolls down a ramp, starting from rest. After 2 seconds, its velocity is 6 meters per second. What is the acceleration of the ball? Acceleration = V f – V i t

11. Graphing Acceleration

12. Acceleration is graphed on a speed / time graph Accelerated motion will be a curve Constant acceleration will be a straight line on a speed/time graph Horizontal lines on a speed / time graph indicates the object is moving at a constant speed..

13. Graphing Acceleration