1. Position vs Time Graphs

2. Position vs Time Graphs
Reading
Position vs Time Graphs
Think about it
Look at the Axes Titles First!
What does the graph say about the object’s motion?
Practice

3. Position-Time Graphs 1 2 3 4 5 6 7 8 9 10
position (cm)
time (s)

4. Position vs. Time Graphs
x-axis: Time
y-axis: Position
slope = Velocity
horizontal line: at rest
straight line: constant velocity
positive slope = positive velocity
negative slope = negative velocity
curved line: changing velocity

5. Position-Time Graphs
The slope of a P-T graph is equal to the object’s velocity in that segment.
slope =
change in y
change in x
time (s)
position (m) 10 20 30 40 50
slope =
(30 m – 10 m)
(30 s – 0 s)
slope =
(20 m)
(30 s)
slope = 0.67 m/s

6. Position vs. Time Graphs
Determine the velocity from each of the above graphs.
Which graph has a greater speed, the top right graph or bottom left graph?

7. Position vs. Time Graphs
What is happening to the velocity of an object whose position-time graph looks like this? What is this object doing?

8. Position-Time Graphs
The following P-T graph corresponds to an object moving back and forth along a straight path. Can you describe its movement based on the graph?
time (s)
position (m) N S