Question

A car moves of a circular track of radius $\frac{7}{22}$ km. After its start, when its displacement becomes zero for the first time, the distance covered by the car is

• A. $2km$
• B. $2\pi km$
• C. $0$
• D. $200m$

Answer 1

Answer: (A)

$2km$

Displacement of the moving car on a circular track equals zero when the car completes one complete circle. So, for the first time displacement become zero when it completes one full circle.
The car moves on a circular track.
So, its displacement becomes $0$ for the first time when it completes one full round on the track.
The distance travelled will be the perimeter of the circular road.
Radius of the circular road = $\frac{7}{22}km$
$\therefore$ perimeter $=2\times \pi \times \frac{7}{22}km=2\times \frac{22}{7}\times \frac{7}{22}km=2km$
Distance covered by the car is $2km$.