Question

2. A car travels 22 km south, 12 km west, and 14 km north in half an hour. (See the figure below)

a) What is the average speed of the car?

b) What is the final displacement of the car?

c) What is the average velocity of the car?

Answer 1

a) What is the average speed of the car?

$$v_{\rm ave}=\frac{22+12+14}{0.5}=9.6\:\rm km/hr$$

b) What is the final displacement of the car?

$$d=\sqrt{(22-14)^2+12^2}=14.4\;\rm km$$

c) What is the average velocity of the car?

$$|{\vec v}_{\rm ave}|=\frac{14.4}{0.5}=28.8\:\rm km/hr$$