Advertisements
Advertisements
प्रश्न
A boy standing in front of a wall at a distance 17 m produces 10 claps per second. He notices that the sound of his clapping coincides with the echo. Echo is heard only once when clapping is stopped. Calculate the speed of sound.
उत्तर
Let d be the distance of the wall from the boy.
To hear the echo, the sound has to travel a distance.
2d = 2 × 17 = 34 m.
Since 10 claps are produced in one second, therefore each clap is produced after 1/10 s which is equal to the time taken for the echo to be heard (according to the question), i.e., t = 1/10 s = 0.1 s.
Now speed of sound V = `"Distance travelled"/"Time taken"=34/0.1`
= 340 ms−1.
APPEARS IN
संबंधित प्रश्न
The wavelength of waves produces on the surface of water is 20 cm. If the wave velocity is 24 m s-1, calculate:
- the number of waves produced in one second, and
- the time in which one wave is produced.
What should be the minimum distance between source and reflector in water so that echo is heard distinctly?
(The speed of sound in water = 1400 m s-1)
A man standing 48 m away from a wall fires a gun. Calculate the time after which an echo is heard. (The speed of sound in air is 320 ms-1).
A ship on the surface of water sends a signal and receives it back from a submarine inside water after 4 s. Calculate the distance of the submarine from the ship. (The speed of sound in water is 1450 ms-1)
A person standing between the two vertical cliffs produces a sound. Two successive echoes are heard at 4 s and 6 s. Calculate the distance between the cliffs.
(Speed of sound in air = 320 ms-1)
What is the range of audibility?
A sound made on the surface of a lake takes 3 s to reach a boatman. How much time will it take to reach a diver inside the water at the same depth?
Velocity of sound in air = 330 ms−1
Velocity of sound in water = 1450 ms−1
A boy stands 66.4 m in front of a high wall and then blows a whistle. Calculate the time interval when he hears an echo. (Speed of sound = 332m/s).
The wavelength and frequency of the sound wave in a certain medium is 40 cm and 835 Hz respectively. In the same medium if another wave has a wavelength equal to 32 cm, calculate its frequency.
A man standing in front of a vertical cliff fires a gun. He hears an echo after 35s. On moving close to the cliff by 82.5 m he fires again. This time he hears the echo after 2.55s. Calculate the speed of sound, distance, and the initial position of man from the cliff.
