Example

Carol is jogging at constant velocity. Below is the displacement-time graph for the first 10 s of her jog.

Displacement-time graph for the first 10 seconds of a jog.
Question

What is Carol’s displacement after 6 s?

Carol’s displacement is 24 m.

Question

What is Carol’s velocity?

velocity = gradient of displacement-time graph = displacement ÷ time

displacement = 40 m – 0 m = 40 m

time = 10 s – 0 s = 10 s

velocity = displacement ÷ time= 40 m ÷ 10 s = 4 m/s

Carol’s velocity is 4 m/s.

Question

If Carol continues to jog at the same velocity how far will she have travelled after 22 seconds?

displacement = velocity x time

displacement = 4 m/s x 22 s = 88 m

Carol will have travelled 88 m.