Question

A car runs at a constant speed on a circular track of radius 100 m, taking 62.8 s for every circular lap. The average velocity and average speed for each circular lap respectively is :

• A. 0, 0
• B. 0, 10 m/s
• C. 10 m/s, 20 m/s
• D. 20 m/s, 0

Answer 1

Answer: (B)

0, 10 m/s

Answer 2

100m is the lap radius.
Circumference = 2$\pi$R = 200$\pi$ = 628 metres
It takes 62.8 seconds to complete one lap.
Consequently, average speed =$\frac{62.8}{628}$ = 10 m/s.
After finishing a lap, the initial and end positions are the same, hence the average velocity is 0 (displacement = 0).

Therefore, the correct option is (B): 0, 10 m/s