1. Distance Time Graphs Time is always plotted on x axis
Distance is always plotted on y axis
To figure average speed, divide distance by time

2. Distance-time graphs 2) Horizontal line = Stopped, not moving 40 30 2010
4) Diagonal line downwards = returning to start
Distance
(meters)
3) Steeper diagonal line = faster the motion
Time/s
Diagonal straight line = moving at constant speed

3. Distance – time Graphs
Line is curving upwards – shows increase in speed
It is accelerating.
Curving downwards – shows decrease in speed,
It is still accelerating – change in speed

4. 40 30 20 10
Distance
(meters)
Time/s
What is the speed during the first 20 seconds?
What is happening between 20 and 40 seconds?
How far is the object from the start after 60 seconds?
What is the speed during the last 40 seconds?
When was the object travelling the fastest?

5. How to calculate slope Slope = y2 – y1 X2 - X1 Rise divided by Run
25- 5 = 20
Slope = 4 m/s

6. Question
What does the slope of a distance vs. time graph show you about the motion of an object?
It tells you the SPEED

7. Leroy is the fastest. He completed the race in 3 hours
Question
Below is a distance vs. time graph for 3 runners. Who is the fastest?
Leroy is the fastest. He completed the race in 3 hours

8. Speed Time Graphs Time in plotted on X-axis
Speed or velocity is plotted on Y-axis
Shows acceleration

9. Speed-time graphs 1) Upwards line = object is accelerating 80 6040 20
4) Downward line = object is decelerating
Velocity
m/s
3) Upwards line =
2) Horizontal line = speed is constant
T/s

10. 80 60 40 20
Velocity
m/s
T/s
How fast was the object going after 10 seconds?
What is the acceleration from 20 to 30 seconds?
What was the deceleration from 30 to 50s?
How far did the object travel all together?