Example
Carol is jogging at constant velocity. Below is the displacement-time graph for the first 10 s of her 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 Ă· time
displacement = 40 m – 0 m = 40 m
time = 10 s – 0 s = 10 s
velocity = displacement Ă· time= 40 m Ă· 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.