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

Question

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

Tardigrade Admin · Accepted Answer

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

\Rightarrow d = 340 \times 1 = 340 m

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 340ms−1, the distance between the cliffs is

680 m

1700 m

340 m

1620 m

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) 2×2d​=v×t ⇒d=340×1=340m

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 $340 m s^{- 1}$ , the distance between the cliffs is

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)
$2 \times \frac{d}{2} = v \times t$
$\Rightarrow d = 340 \times 1 = 340 m$