1. Distance / time graphs

2. Lesson aims To show speed as a graph.
To identify graphs showing constant and changing speed.
To calculate speed, distance and time at points on a graph.

3. No movement?
distance
Ask a student to sketch on whiteboard.
time

4. No movement
distance
time

5. Constant speed?
distance
Ask a student to sketch on whiteboard.
time

6. Constant speed
distance
time

7. Constant speed
How would the graph look different for a faster constant speed (walking to Science)?
distance
Ask a student to sketch on whiteboard.
time

8. Constant speed
fast
distance
time

9. Constant speed
fast
How would the graph look different for a slower constant speed (walking to any class but Science)?
distance
Ask a student to sketch on whiteboard.
time

10. Constant speed
fast
distance
slow
time

11. The gradient of the graph gives the speed
Constant speed
fast
The gradient of the graph gives the speed
distance
slow
time

12. Getting faster? (accelerating)
distance
Ask a student to sketch on whiteboard.
time

13. Getting faster (accelerating)
distance
time

14. Examples
distance
time

15. A car accelerating from stop and then hitting a wall
distance
Ask a student to sketch on whiteboard.
time

16. A car accelerating from stop and then hitting a wall
distance
time

17. How far had the object gone after 20 seconds? 40 30
Distance
(metres)
Distance
(m) 20 10
Time/s 20 40 60 80
100
Time (s)
How far had the object gone after 20 seconds?
How far had the object gone after 60 seconds?
When is the object standing still?
When was the object traveling the fastest?

18. A man left home at 12 noon to go for a cycle ride
A man left home at 12 noon to go for a cycle ride. The travel graph represents part of the man’s journey.
For how many minutes did he rest?
2. Find his distance from home at 1.30pm.
15 minutes
15 km

19. What is happening between 9AM and 11AM? Constant speed
What is happening between 9AM and 11AM?
2. What do you think bicyclist is doing between 11AM and 1PM?
3. What was the total distance covered from 11AM to 4PM?
Constant speed
Stopped to rest
30 miles

20. Distance-time graphs 2) Horizontal line = 40 30 20 10
4) Diagonal line downwards =
Returning to start
No movement
Distance
(metres)
3) Steeper diagonal line =
Time/s
Diagonal line =
Constant speed
Faster constant speed

21. Work to be done today Worksheet – distance / time graphs
Make up a distance / time graph to show a journey you could make. (It doesn’t have to be on foot). Write about what is happening at each stage of the journey.