1. VELOCITY-TIME GRAPHS

2. Site of airplane crash

3. Crash site of flight 93

4. Typical plane crash v-t graph

5. Velocity- time set up • The vertical axis is measured in m/s • Positive number represent forward motion • Negative numbers represent backward motion • The horizontal axis is measured in s

6. Horizontal lines on a V-T graph Velocity (m/s) Time (s)

7. Determine direction on V-T graph Any portion of graph above the zero line denotes forward motion Any graph on line, means object at rest

8. Tilted lines on V-T graphs V (m/s) T (m/s)

9. Tilted lines on V-T graphs V (m/s) T (m/s)

10. What do tilted lines mean on a V-T graph? The object is changing its velocity Acceleration How it accelerates is determined by Location of graph (Above, Below x-axis) Type of tilt

11. Acceleration is… A change in the velocity of the object Tilted lines on a V-T graph indicate acceleration Acceleration can be calculated by finding the slope value of these lines

12. What kind of motion is indicated on this graph? V (m/s) T (s)

13. Constant Velocity or Acceleration? Horizontal lines represent CV Slanted lines represent ACC

14. Faster or slower? Tilt towards zero line = slower Tilt away from zero line = faster

15. What would curves mean on a V-T graph Curves would indicate non-constant acceleration Think roller coaster rides, when you get pushed against the harness or back into the seat The ‘Jerk’

16. Identify motion for each part of the V-T graph V (m/s) T (m/s)

17. Create a V-t graph that… Section 1: Shows constant motion of (-3) m/s for 5 seconds. Section 2: Shows constant acceleration (slowing down in the negative direction) Section 3: Shows no movement for 5 seconds Section 4: Shows constant acceleration (speeding up in the positive direction)

18. Answer

19. VERTICAL LINES?

20. Can there be a vertical line in a graph of a real object’s motion?

21. No That would mean that the object is at several places at an instant of time

22. DIFFERENCES BETWEEN POSITION AND VELOCITY TIME GRAPHS

23. Differences between V-t graphs and P-T graphs The vertical #’s tell how fast, not location V-t does not indicate start position Direction is indicated by position on graph, not slope Acceleration is indicated differently on each type of graph

24. CALCULATE OVERALL DISPLACEMENT

25. On V-T graph, what is the area equal to? 5 m/s 10 s

26. How do you find the overall Displacement, Distance from a V-t graph? How far does an object travel if it moves at 5 m/s for 10 seconds? V = d / t  d = t x V  5 x 10 = 50 m

27. Finding overall displacement from V-T graph How far does an object travel if it goes 3 m/s for 10 seconds? V 3 t 10

28. To find displacement To find displacement of any section Find the area under the graph Any section that is above the x-axis is positive displacement Any section below the x-axis is negative displacement Combine displacements for overall velocity