The gradient of a distance-time graph represents speed. When displaying a journey, the vertical axis will often represent the distance from a particular place rather than the distance travelled.

Example: Using the gradient or slope of a distance - time graph to work out the speed of an object Calculate the speed of the object represented by the green line in the graph below, from 0 to 3 s.

According to our kinematic equation, distance should be proportional to time squared. Let's make another graph. First, I am going to put distance on the vertical axis.