Answer:
Average speed = 2.22m/s
Velocity = 0.89 m/s west
Explanation:
(i) Since speed is a scalar quantity, the direction of movement by the person is irrelevant. Therefore,
Average speed = total distance traveled / time taken
Where;
Total distance = 70m + 30m = 100m
Time taken = 45 seconds
Average speed = 100 / 45 = 2.22m/s
(ii) However, velocity is a vector quantity and so the direction of movement by the person is of utmost importance. Therefore,
Velocity = displacement / time taken
Where;
displacement = -70m + 30m [West direction is taken as negative and east is taken as positive]
displacement = -40m [The negative sign just means that the net displacement is in the direction of the West].
Thus, displacement can be written as 40m west.
Therefore,
Velocity = 40 / 45 = 0.89m/s west
