Advertisements
Advertisements
Question
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)
Solution
t = 0.1 sec,
v = 1400 m/s
t = `(2d)/v`
Or d = `(tv)/2`
= `(0.1 xx 1400)/2`
= 70 m
APPEARS IN
RELATED QUESTIONS
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.
Calculate the minimum distance in air required between the source of sound and the obstacle to hear an echo. Take speed of sound in air = 350 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)
On sending an ultrasonic wave from a ship towards the bottom of a sea, the time interval between sending the wave and receiving it back is found to be 1.5 s. If the velocity of wave in sea water is 1400 m s-1, find the depth of the sea.
The smoke from the gun barrel is seen 2 seconds before the explosion is heard. If the speed of sound in air is 340 ms−1, calculate the distance of the observer from the gun. State the approximation used.
An observer standing in front of a vertical wall claps 10 times one second. He adjusts his distance from the wall in such a way that the second of his clapping coincides with the echo. This happens when bis distance from the wall is 17.5m. What is the velocity of sound heard by him?
A person fires a gun while standing at a distance of 850 m from a building. If the speed of sound is 350 ms, calculate the time in which the person hears an echo of the gun flte.
A ship which is stationary at a distance of 680 m from the shore, sends a signal to the coast. Its echo is heard in 4s. Find the velocity of sound.
An observer stands at a distance of 850 m from a cliff and fires a gun. After what time gap will he hear the echo? If sound travels at a speed of 350 m/sec., in air.
