1. Describing Motion 1

2. Graphing Motion  Graphing is a good way to easily show motion. Your data will determine which graph that you use. The types of graphs that you can use are: 1.Position- time graphs 2.Velocity time graphs 2

3. 3 Distance-Time Graphs for Uniform Motion Problem  If we prepare a table to show the position of a car at 5 second intervals, then we can plot a graph. t(s)05101520253035404550 d(m)01002003004005006007008009001000

4. 4

5. 5 The distance-time graph for uniform speed is a straight line (constant slope) 1. How far would the car travel during a 20 second interval? 2. How far would it travel between the 25s and 50s interval? 3. How long would it take the car to travel 450m?

6. Distance- Displacement Graphs  The slope of the graph represents the VELOCITY 6

7. 7 Sample Problem 2  the motion of two cars A and B is represented by the following graph. What can we learn about the motion of the cars from the graph?

8. 8 How do we find out?  Slope (Steepness)  One line climbs more steeply than the other. Car A, moves a greater distance within an interval of time. Car A must be traveling faster than car B.  *higher speeds give greater slopes.

9. 9 Let’s find the slope of both of the lines from the previous graph. Car ACar B

10. 10 In this graph, the lines are parallel (equally steep). Vehicle A and B are starting from different positions, but their speeds are the same.

11. Assignment  Domino Dash

12. 12 Speed and Direction This graph represents an object traveling to a certain point, stopping for a while, then returning to its initial position again.

13. 13 Calculate the slope of the 3 intervals: A, B, and C. Interval A  Interval B  Interval C  *slope is negative for interval C because it is traveling in the opposite direction. The object returned to its original position.

14. Non-uniform Motion  Non-uniform motion is the change in speed or direction, or both. A roller coaster is a good example.

15. Assignment  Describing Position-Time Graph(10-1)  The helicopter challenge(10-2)

16. Average Speed  the slope of a graph changes when the speed of the object changes  When an object’s speed changes several times in a trip, the average speed can be calculated by:  Average Speed = total distance traveled v av = d total time for trip t

17. Example: A delivery person travels from Saskatoon to Warman to drop off a parcel. It takes 15 minutes to travel to Warman, 10 minutes to drop off the parcel, and then 20 minutes to get back. What is the speed of the truck to get there? What is the speed of the truck on the way back? What is the average speed of the trip? (The distance from Saskatoon to Warman is 25km)

18. assignment  Uniform motion (10-5)  Velocity from position-time graphs (10-6)