1. How Scientists Record and Plot Motion Data
Graphing Motion
How Scientists Record and Plot Motion Data

2. Notes Write down the words in yellow.
The words in white are discussion points, you may write these down, but are not required.

3. Important Vocabulary
Data – pieces of information including words & numbers
Data Table – a chart made up of columns and rows, used to organize data

4. Important Vocabulary
Line Graph – graph that shows data as a line on a grid. Can show changes over time.
X-axis – graphs horizontal line
Y-axis – graphs vertical line

5. Distance-Time Graphs
Scientists use line graphs to show the motion of an object.
These line graphs are called distance-time graphs; they show the relationship between distance and time.
X-axis = time an object travels
Y-axis = distance an object travels

6. Types of Graphs
Suppose a scientist measures how far a cheetah has run after a certain amount of time. The scientist records the data in the table below.
Cheetah’s Motion
Time (seconds)
Distance (meters) 10
100 15
150 20
200 25
250 30
300

7. The scientist makes a line graph to show the cheetah’s motion.
Types of Graphs
The scientist makes a line graph to show the cheetah’s motion.
Distance-Time Graph for Cheetah
500
400
300
200
100
Distance (meters)
Cheetah
Time (seconds)

8. Constant Speed Graph
Straight line – the speed did not change (remained constant for the time measured)
Distance-Time Graph for Cheetah
500
400
300
200
100
Distance (meters)
Cheetah
Time (seconds)

9. Constant Speed Graph
To find the cheetah’s speed, divide the total distance by the total time.
Speed = Distance/Time
= 300 m/30 sec
= 10 meters per sec
The cheetah moved 10 meters during every second it was running.
Distance-Time Graph for Cheetah
500
400
300
200
100
Distance (meters)
Cheetah
Time (seconds)

10. Stopped Motion Graph
A flat line on a d-t graph = shows an object has stopped moving.
Distance-Time Graph for Cheetah
500
400
300
200
100
Distance (meters)
Cheetah
Time (seconds)

11. Stopped Motion Graph
Distance-Time Graph for Cheetah
500
400
300
200
100
Suppose after 30 sec the cheetah stops moving. After another 10 sec, at 40 sec, the distance traveled is 300 m.
The graph shows that the cheetah had stopped moving.
Distance (meters)
Cheetah
Time (seconds)

12. Graphing Faster Motion
A steeper line on a d-t graph = a faster, or greater, speed.
Distance-Time Graph for Cheetah
500
400
300
200
100
Distance (meters)
Cheetah
Time (seconds)

13. Graphing Faster Motion
Now suppose after 40 sec, the cheetah starts moving again. It travels 200 m in the next 10 sec. The new part of the graph is steeper. It shows that the cheetah moved 200 m in 10 seconds. The cheetah moved faster than it did for the first 30 sec.
Distance-Time Graph for Cheetah
500
400
300
200
100
Distance (meters)
Cheetah
Time (seconds)

14. Let’s Practice What does the x-axis show?
During which period of time did the cat stop moving?
Ex: 0-30 sec
During which period of time did the cat move faster?
Distance Cat Travels over Time
100 90 80 70 60 50 40 30 20 10
Distance (meters)
Time (seconds)

15. Exit Ticket
What is speed? How is it calculated? Find the speed of this object: Distance: 525 cm, Time: 3 seconds
What does a flat, straight line on a Distance/Time graph mean?

16. Practice Motion Graphs information sheet and practice.