The distance covered in 5 s by a body moving with a velocity of 6 m/s is given by,
Distance = velocity x time
= 6 x 5
= 30 m
If we plot a graph of velocity against time for this case a straight-line parallel to the time axis is obtained (Fig. 3.1). On this graph, OC represents the time, 5 s, and OA the constant velocity 6 m/s.
Hence, distance = velocity x time
= OA x OC
= area OABC on the scale of the graph
The distance travelled is thus represented by the area between the velocity-time curve and the time axis. This important result applies in all cases, whatever the shape of the velocity-time curve.