1. Interpreting Motion Graphs

2. Position vs. time graphs
The slope of the graph is equal to the velocity
If the d/t graph is a straight line (no curve) then the velocity is constant.

3. Position vs. time graphs
A line with a positive slope indicates positive velocity and the object is moving away from the reference point
A line with a negative slope indicates negative velocity and the object is moving towards the reference point.

4. Position vs. time graphs
If the line is horizontal (no slope) then the object is stationary (no velocity)

5. Position vs. time graphs
If the object is accelerating, the velocity is changing
d/t graph will no longer be a straight line, but will have a changing slope, resulting in a curve.

6. Position vs. time graphs
When the concavity of the line is “up like a cup”, the acceleration is positive

7. Position vs. time graphs
When the concavity of the line is “down like a frown”, the acceleration is negative

8. Position vs. time graphs
BEWARE: velocity and acceleration can have different signs: when they do the object is slowing down!

9. Velocity vs. time graphs
The slope is equal to the acceleration.
Because we only consider constant acceleration, v/t graphs will always be straight lines.

10. Velocity vs. time graphs
When the slope of the graph is positive:
the acceleration is positive

11. Velocity vs. time graphs
When the slope of the graph is negative:
the acceleration is negative

12. Velocity vs. time graphs
When the slope is zero:
horizontal line
velocity is constant

13. Velocity vs. time graphs
Positive velocity indicates the object is moving away from the reference point

14. Velocity vs. time graphs
Negative velocity indicates the object is moving toward the reference point

15. Velocity vs. time graphs
We cannot determine where an object’s position from a v/t graph, only its change in position.

16. Acceleration vs. time Graphs
Since acceleration is constant, acceleration graphs will always be straight, horizontal lines.

17. Acceleration vs. time Graphs
Since acceleration is constant, acceleration graphs will always be straight, horizontal lines.

18. Acceleration vs. time Graphs
If the line is positive, the acceleration is positive
If the line is negative, the acceleration is negative

19. Acceleration vs. time Graphs
If the line is at zero, there is no acceleration and therefore constant velocity