Physics Two Dimensional Motion Question 332

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

[Kerala (Med.) 2002]

Options:

A) 70 m B) 140 m C) 110 m D)220 m

Show Answer

Answer:

Correct Answer: D

Solution:

Time period = 40 sec No. of revolution$ =\frac{\text{Total time}}{\text{Time period}} $

$ =\frac{140,\sec }{40,\sec }=3.5,Rev $ . So, distance$ =3.5\times 2\pi R=3.5\times 2\pi \times 10=220,m $ .