1. 9/9 We will be working on graphs this week Turn in your completed WS II from yesterday to the blue sorter Pick up Page 2 of Graphing Notes Tests are graded. Corrections/Retakes will be available Tue – Fri Warm Up 3: What is difference between interpolate and exctrapolate?

2. 9/10 Yesterday we covered notes on Displacement vs Time Graphs. You also turned in WS II. Tests are graded. Corrections/Retakes will be available Tue – Fri (I have duty this afternoon from 2:35-2:50) Warm Up 4: Look at graph below. What is the net displacement?

3. The graphs… Game

4. Motion Graphing Distance, Velocity, and Acceleration Motion Graphing Reference

6. Scalar quantity a measurement Magnitude No direction implied Ex. mass, volume, density, distance, speed

7. Vector quantity a measurement Magnitude Direction Ex.: displacement, velocity, acceleration, force

8. Distance the length of the actual path taken by the object regardless of direction scalar quantity SI units include m, km

9. Displacement length (measured in a straight line) from the reference point to the object (implies a given direction) Sometimes on graph labeled as Position vector quantity SI units include m, km

10. Speed change in distance divided by change in time (d/t ) scalar quantity SI units include m/sec or cm/sec.

11. Velocity speed in a given direction magnitude and direction included in the measurement vector quantity SI units include m/sec or cm/sec.

12. Acceleration change in velocity divided by change in time (∆v/∆t) vector quantity SI units include m/sec 2 or cm/sec 2

13. To begin, consider a car moving with a constant, rightward (+) velocity of 10 m/s What would a Position vs Time graph of this motion, look like?

14. The slope of the line on a position-time graph is the velocity of the object.

15. And the slope is…

16. Example 1 A car moves in a straight line and its odometer readings are plotted against time. a. Find the speed of the car at points A and B. = 0.5 m/s A B Same for A and B b. What is the car's average speed? = 0.5 m/s c. What is its acceleration? a = 0 m/s 2 msms

17. Ex 2. Let’s compare the motions shown here Compare the velocity of the red line to the… Green lineBlue line Black line Orange line And this trip shows?

18. Now consider a car moving with a changing, rightward (+) velocity that is, a car that is moving rightward and speeding up or accelerating. And the graph’s shape is?

19. Ex 3. What if the shape of the graph is a curve? A curve shows a changing velocity or acceleration. We can find the Velocity at a particular Instant. If we compare two points, we will See that velocity is changing and therefore We have acceleration.

20. The instantaneous velocity of an object at a certain time is the slope of the position (displacement) versus time graph at that time. It can be positive, negative, or zero. What shows the instantaneous speed in the car?

21. Summary of D v T &V vT No motion, constant velocity, and acceleration on VvT graph

22. d vs t graph Slope of line is velocity Linear line represents a constant velocity Horizontal line represents no motion Curved line represents acceleration Steeper slope represents greater velocity Slope =  d /  t = velocity Distance from detector CAN be indicated

23. Positive direction? Negative direction? Resting? Traveling at same speed?

24. v vs t graph Slope of line is acceleration Linear line represents uniform acceleration Horizontal line represents constant velocity, a=o Curved line represents changing acceleration Steeper slope represents greater acceleration Slope =  v /  t = acceleration Distance from detector cannot be indicated, only direction: away is positive and towards is negative

25. a vs t graph Linear line– acceleration is changing at a constant rate Horizontal line– uniform acceleration(the acceleration stays the same) Curved line– acceleration is changing non- uniformly Steeper slope-- greater change in a Slope =  a /  t

26. Obj 15: Comparing graphs No motion (v=0)

27. Constant Velocity (a=0) positive direction

28. Constant velocity (a=0) negative direction

29. The graphs….

30. In this lab you will measure your motion with a sonic motion detector. The motion detector emits sound waves and then detects them after they have reflected off of some object (such as you or your lab partners!). A computer then records distance from the detector to the object as a function of time. You will practice making and interpreting position-time graphs.