Q. A man, standing between two cliffs, claps his hands and starts hearing a series of echoes at intervals of one second. If the speed of sound in air is $340\ ms^{- 1}$, the distance between the cliffs is
A) 680 m
B) 1700 m
C) 340 m
D) 1620 m
Explanation
(c) Let the distance between the two cliffs be d. since, the man is standing midway between the two cliffs, then the distance of man from either end is d/2
The distance travelled by sound (in producing an echo)
$2 \times \frac{d}{2} = v \times t$
$\Longrightarrow \ \ \ \ d = 340 \times 1 = 340m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.