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
Concave “Up like a cup”…the acceleration is positive

7. Position vs. time graphs
Concave “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
Positive velocity indicates the object is moving away from the reference point

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

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

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

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

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