1. Speed and Distance-Time Graphs

2. Speed
Speed is the distance traveled divided by the time it takes to travel that distance.
The faster something is moving, the less time it takes to travel a certain distance.

3. d = st d s t

4. Practice Problems
Mary drives 40 meters in 2 seconds. What is her average speed in the car for these two seconds?

5. 2. David runs 400 meters in 50 seconds
2. David runs 400 meters in 50 seconds. What is his average speed over this distance?

6. 3. Adrian is running at a speed of 7 m/s. If he runs at
3. Adrian is running at a speed of 7 m/s. If he runs at this speed for 5 seconds, how many meters will he have run?

7. 4. Tim jogs at a speed of 5 m/s for a distance of 60. meters
4. Tim jogs at a speed of 5 m/s for a distance of 60 meters. How much time does this take him?

8. Distance-Time Graphs B A C D

9. Interpreting points from d-t graphs
Each point has y-coordinate and x- coordinate
Y-coordinate tells you the total distance object has gone from starting point.
X-coordinate tells you the total time that has passed since object started moving.
Point C: (7, 8)
x = 7 s
y = 8 m

10. Practice B A C D
At point B, how far had the object traveled, and how much time had passed?
After 1 second, how many meters had the object traveled?
How many seconds did it take for the object to travel 6 meters?

11. Calculating speed from d-t graphs
To find object’s speed between two points:
Find the change in y-coordinates (y2 – y1)
Find the change in x-coordinates (x2 – x1)
Divide change in y by change in x

12. Independent practice time!

13. Example
Average speed, point A to point B: B A C D

14. Practice
What was the average speed during segment A?

15. Practice
What was the average speed during segment B?

16. Practice
What was the average speed during segment C?

17. Practice
What was the average speed during segment D?