Distance-Time Graphs

Distance-time graphs help us visualise how far an object travels in a given period of time. Below is an example of a distance-time graph.

The time in seconds (s) is always on the x-axis and the distance in metres (m) is always on the y-axis.


The gradient on the distance-time graph (how steep the line is) tells us the speed of the object. The steeper the line is, the faster the speed of the object is.

  • We can calculate the gradient at different points on the graph to find out the speed of the object at different points in time.

Therefore, the gradient of the line is:

The delta symbol (Δ) means change. So in this case, ΔD means change in distance and ΔT means change in time.

Features of Distance-Time Graphs

When looking at a distance-time graph, we can identify important features:

  • Straight lines represent a constant speed (constant gradient)
  • Horizontal lines represent a stationary object (the object has stopped and at this point, the gradient is 0)
  • A steepening curve represents an accelerating object (increasing gradient)
  • A flattening curve represents a decelerating object (decreasing gradient)