MEDIUM
Earn 100

Define reverberation.

Important Questions on Sound

EASY
Sound travels at a speed of 1450 ms-1through water. A submarine detects objects around it by sending sound waves and detecting echo (reflected sound) heard after 4 s. Then the object must be at a distance of:
EASY
If the velocity of sound in air is 340 m s-1 and x is the minimum distance between sound source and reflecting surface to get echo from general sound, then :
EASY

A person clapped his hands near a cliff and heard the echo after 4 s. The distance between the cliff and the person will be :

(Speed of sound is 346 m s-1

MEDIUM
Name the system which enables us to locate underwater objects by transmitting ultrasonic waves and detecting the reflecting impulse.
EASY
What is the difference between reverberation and echo?
EASY
What is the minimum distance required to hear an echo in air?
EASY
A girl drops a ball from a height h=20 m. It strikes the ground elastically and returns to her hand. An echo of the thud of the ball striking the ground is produced from a nearby cliff. The echo is head at exactly the same moment when the ball returns to the girl's hand. (Take g = 10 ms-2  and vsound=350 ms-1). The distance of the cliff from the girls is close to:
EASY
Sound signal from a ship floating in water hits the bottom of the sea and reflects back to the ship after 6 s. Speed of sound in water is 1500 m s-1. Calculate the depth of the sea.
EASY
A man who is standing at a distance of 850 m from a sound reflecting surface claps loudly. If the velocity of the sound in air is 340 ms-1 then the time taken by the echo to reach him is
HARD
A pendulum  has a frequency of 4 vibrations per second. An observer starts the pendulum and fires a gun simultaneously. He hears the echo from the cliff after 6 vibrations of the pendulum. If the velocity of sound in air is 340 ms-1, find the distance between the cliff and the observer. 
EASY
A person clapped hands near a wall and heard the echoes after 5 s. What is the distance of the wall from the person, if the speed of the sound at that time was 346 ms?  
EASY
What are the conditions necessary for the formation of an echo?
EASY
Name a place where you can experience echo.
MEDIUM

What is an echo? Explain how the principle of echo is used by

a. bat during its flight at night and

b. a dolphin to locate small fishes as its prey. 

EASY
How long does sound persist in our ears?
EASY
An echo is heard 0.6 s after a person bursts a cracker at a distance of 102 m from a high building. Calculate the speed of the sound.
MEDIUM
What is meant by an echo? How is it heard? Explain the various conditions necessary for the formation of echoes.
EASY
For doing the experiment on the verification of laws of reflection of sound,
EASY
Warning sounds include _____.
EASY
Why do we not hear echo at all places?