1. Graphing motion

2. The velocity of an object can be found by determining the SLOPE on a position-time graph.

3. A changing velocity results in a curve on a position vs. time graph

4. Careful. This is not a position vs. time graph
Careful! This is not a position vs. time graph! Acceleration can be determined from a velocity vs. time graph
The acceleration is found by taking the slope of a velocity vs time graph.

5. Velocity vs time graph
Is this a graph of “uniform” velocity? Is the velocity increasing or decreasing? What is the name for the rate that velocity changes?

6. The displacement is found by taking the area of a velocity vs time graph.
The area of a triangle is ½ bh;
the area of a rectangle is length X width
The area under the x-axis must be subtracted from the areas above the x-axis.

7. Velocity-Time Graphs
Velocity (m/s) 8 6 4 2 -2 -4 -6 -8
Time (s)
What is the velocity?
At 1 s?
At 4 s?
At 7 s?
At 12 s?
At 17 s?
What is the acceleration?
From 0 – 2s?
From 2 – 6 s?
From 9 – 11 s?
From s?
From 14 – 22 s?
The ACCELERATION is found by taking the SLOPE of the velocity vs. time graph

8. Velocity-Time Graphs Acceleration = slope
Velocity (m/s) 8 6 4 2 -2 -4 -6 -8
Time (s)
What is the velocity?
At 1 s? 6m/s
At 4 s? 3m/s
At 7 s? 0
At 12 s? -8m/s
At 17 s? -4m/s
What is the acceleration?
From 0 – 2s? 0
From 2 – 6 s? -1.5 m/s2
From 9 – 11 s? -4m/s2
From s? 0
From 14 – 22 s? +1.4m/s2
Displacement from the starting point = the area of the shapes. Shapes below the x- axis will be negative displacement!
What about the displacement?
Acceleration = slope