Displacement-Time Graphs

Displacement-time graphs show an object’s position relative to its starting point over a period of time. They’re useful because they can be used to describe an object’s motion as well as find its velocity at a given point.

Plotting displacement-time graphs

Let’s see how to plot displacement-time graphs for moving objects.
The suvat equations can be used to work out values to plot.

Displacement is plotted on the y-axis and time on the x-axis.

Let’s solve a problem to understand the procedure of plotting a displacement-time graph.

Plot a displacement-time graph for a panther who accelerates constantly from rest at 2.0 ms^–2 for 5.0 seconds.

Solution:

Known values:

Acceleration = a = 2 ms^–2

Initial velocity = u = 0

To find the displacement, we will use this suvat equation: s = ut + (1/2)at²

Here, u =0.

Hence, we can write: s = (1/2)at² ………. (1)

Here, s = (1/2) 2. t² = t²

Now pick values of t between 0 and 5.0 seconds
and work out the values of s at those points with s = t²: …then plot the graph:

Displacement is plotted on the y-axis and time on the x-axis.