Question

An ant completes moving along a circle in time 5 s. At that speed, how much time will it take to travel along the diameter and come back?

• A. 1.59 s
• B. 6.36 s
• C. 3.18 s
• D. 5.26 s

Answer 1

The correct option is C 3.18 s

Let us take the radius of the circle to be r.

The distance covered by the ant is $2\pi \times r$

Time = 5 s

Speed = $\frac{2\pi \times r}{5}$

Now with the same speed, the ant travels along a diameter and comes back to the initial position.

Distance covered = 4r

Speed = $\frac{2\pi \times r}{5}$

Hence, time taken = $\frac{4r}{\frac{2\pi \times r}{5}}$

$=\frac{2}{\pi }\times 5=\frac{2}{3.14}\times 5=3.18s$