Question

An athlete completes one round of a circular track of diameter $200m$ in $40s$. What will be the distance covered and the displacement at the end of $2$ minutes $20s$?

Answer 1

Given : Diameter of the circular track $D=2R=200$ m

Time $t=2$ minutes $20$ s $=140$ s

As the athlete completes one round in 40 seconds, thus he will be at point B after 140 seconds by covering three and half rounds.

$\therefore$ Displacement of the athlete $s^{\prime }=2R=200$ m

Distance covered $d=3.5\times \left(2\pi R\right)$

$d=3.5\times \frac{22}{7}\times 200=2200$ m