Sunil is standing between two walls. The wall closest to him is at a distance of 360m. If he shouts, he hears the first echo after 4 seconds and another after another 2 seconds.
1. What is the velocity of sound in air?
2. What is the distance between the two walls?

Open in App

Solution

1. Time to hear first echo $= 4 s$
Distance travelled by sound in these $4 s = 360 \times 2 m$
Speed of sound $= \frac{360 \times 2}{4} = 180 m / s$
2. Time taken to hear second echo $= 4 s + 2 s = 6 s$
Distance travelled in these $6 s = 2 x$
Speed of sound in air $= 180 m / s$
Therefore, $2 x = 180 \times 6$
$x = 540 m$
Distance between the walls $= 540 + 360 = 900 m$

Suggest Corrections

Similar questions

Solve the following examples.

a. The speed of sound in air at 0^oC is 332 m/s. If it increases at the rate of 0.6 m/s per degree, what will be the temperature when the velocity has increased to 344 m/s?

b. Nita heard the sound of lightning after 4 seconds of seeing it. What was the distance of the lightning from her?(The velocity of sound in air is 340 m/s?)

c. Sunil is standing between two walls. The wall closest to him is at a distance of 360 m. If he shouts, he hears the first echo after 4 s and another after another 2 seconds.

1. What is the velocity of sound in air?

2. What is the distance between the two walls?

d. Hydrogen gas is filled in two identical bottles, A and B, at the same temperature. The mass of hydrogen in the two bottles is 12 gm and 48 gm respectively. In which bottle will sound travel faster? How may times as fast as the other?

e. Helium gas is filled in two identical bottles A and B. The mass of the gas in the two bottles is 10 gm and 40 gm respectively. If the speed of sound is the same in both bottles, what conclusions will you draw?

Q. A man stands in between two cliffs and fires a gun. He hears two successive echoes after 3 seconds and 5 seconds. What is the distance between two cliffs? [Speed of sound

= 330 m s^{- 1}]

A person is standing at a distance of $d m$ from a wall and clapping at a rate of $4$ claps per second. The echo of his clap coincides with his clap and he hears the echo of two claps after he stops clapping. What is $d$ ? (Assume velocity of sound to be $340 m / s$ )

Join BYJU'S Learning Program

Sunil is standing between two walls. The wall closest to him is at a distance of 360m. If he shouts, he hears the first echo after 4 seconds and another after another 2 seconds.1. What is the velocity of sound in air?2. What is the distance between the two walls?

1. Time to hear first echo =4s Distance travelled by sound in these 4s=360×2mSpeed of sound =360×24=180m/s2. Time taken to hear second echo =4s+2s=6sDistance travelled in these 6s=2xSpeed of sound in air =180m/s Therefore, 2x=180×6 x=540m Distance between the walls =540+360=900m

Sunil is standing between two walls. The wall closest to him is at a distance of 360m. If he shouts, he hears the first echo after 4 seconds and another after another 2 seconds.
1. What is the velocity of sound in air?
2. What is the distance between the two walls?