Distance-Time Graphs

Distance-Time Graphsvideo

Distance-time graphs

How do I use a distance-time graph?

• Distance-time graphs show the distance travelled at different times

  • Distance is on the vertical axis

  • Time is on the horizontal axis 

• The gradient of the graph is the speed

  • $\mathrm{speed} = \frac{\mathrm{distance}}{\mathrm{time}} = \frac{\mathrm{rise}}{\mathrm{run}}$

• The steeper the line the faster the object is moving

  • Lines with positive gradients represent objects moving away from the start point

  • Lines with negative gradients represent objects moving towards the start point

  • Lines that are horizontal represent rest

    • The object is stationary (not moving)

How do I work out the overall average speed?

• For journeys with multiple parts

  • the overall average speed for the whole journey is $\frac{\mathrm{total} \mathrm{distance} \mathrm{travelled}}{\mathrm{total} \mathrm{time}}$

  • The total time includes any rests