distance - time graphs

A distance–time graph shows how far something travels over a period of time. It helps us see and describe motion — whether something is moving, stopped, or speeding up.

• The horizontal axis (x-axis) shows time (e.g. seconds, minutes, hours).

• The vertical axis (y-axis) shows distance (e.g. metres, kilometres).

Each point on the graph shows how far the object has gone at a certain time.

Distance-time graphs are graphs that show the distance an object or person has travelled against time. They can also be referred to as travel graphs. A distance-time graph will show the distance (in metres, kilometres, miles etc.) on the vertical axis (y-axis) and the time (in seconds, minutes, hours etc.) on the horizontal axis (x-axis).

Straight lines on a distance-time graph represent constant speeds. To find the speed from a distance-time graph you will need to be able to find the gradient of the straight lines.

The steeper the gradient, the faster the object is travelling.

how to read distance-time graphs

In order to read distance-time graphs:

• Locate any relevant points from the distance-time graph.

• Check the information required. For example, distance travelled at a selected time, period of being stationary, speed at a selected point in the journey.

• Use the appropriate process from the list.

• Distance travelled at a selected time – read from the vertical axis at the given time.

• Period of being stationary – find the time when the line is horizontal.

• Speed at a selected point in the journey – find the gradient of the line at that time or think how far has the object travelled in one time unit.

• Average speed for the whole journey – divide the total distance travelled by the total time.

examples

key ideas to remember

• The steeper the line, the faster the speed.

• A flat line means no movement.

• You can find speed by calculating