Question

An athlete completes one round of a circular track of radius 10 m in 40 sec. The distance covered by him in 2 min 20 sec is

• A. 70 m
• B. 140 m
• C. 110 m
• D. 220 m

Answer 1

Answer: (D)

220 m

Answer 2

$\text{No. of revolution}(n) = \frac{\text{Total time of mo} ⥂ ⥂ \text{tion}}{\text{Timeperiod}} = \frac{140\sec}{40\sec = 3.5}$Distance covered by an athlete in revolution$= n(2\pi r) = 3.5(2\pi r) = 3.5 \times 2 \times \frac{22}{7} \times 10$= 220 m.