Forces
Motion Graph Calculations
To use areas under velocity–time graphs to calculate displacement and distance travelled.

What you will learn

How to find speed from a distance–time graph

How to calculate acceleration from a velocity–time graph

How to find displacement from the area under a graph

How to work with different sections of a graph

How to choose the right graph method for a question
Explanation
The area under a velocity–time graph gives displacement, including signs when velocity is negative. For motion in one direction, this area also gives distance; total distance uses the magnitudes of areas on both sides of the time axis. Calculate rectangular and triangular areas and divide complex graphs into simpler shapes. Use the stated equation and consistent units to obtain a numerical result, then check whether its size and direction fit the physical situation. Give a reason. Compare cases.
