HARD

Earn 100

If you shout or clap in a mountain's region especially, after a while you will hear the same sound, and sound made in big hall persists for a long time.Why?

Important Questions on Sound

EASY

Science>Physics>Sound>Reflection of Sound

A man standing in front of a vertical cliff fires a gun. He hears the echo after

3.5 \sec

. On moving closer to the cliff by

84 m

, he hears the echo after

3 \sec

. Calculate the distance of the cliff from the initial position of the man.

EASY

Science>Physics>Sound>Reflection of Sound

What is the minimum distance required to hear an echo in air?

EASY

Science>Physics>Sound>Reflection of Sound

What is the difference between reverberation and echo?

MEDIUM

Science>Physics>Sound>Reflection of Sound

Name the system which enables us to locate underwater objects by transmitting ultrasonic waves and detecting the reflecting impulse.

EASY

Science>Physics>Sound>Reflection of Sound

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

Science>Physics>Sound>Reflection of Sound

Sound travels at a speed of

1450 {ms}^{- 1}

through 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

Science>Physics>Sound>Reflection of Sound

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.

HARD

Science>Physics>Sound>Reflection of Sound

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

Science>Physics>Sound>Reflection of Sound

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 $346 m s^{- 1}$ )

EASY

Science>Physics>Sound>Reflection of Sound

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

v_{sound} = 350 {ms}^{- 1}

). The distance of the cliff from the girls is close to:

EASY

Science>Physics>Sound>Reflection of Sound

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

MEDIUM

Science>Physics>Sound>Reflection of Sound

The sound heard after reflection is _____.

EASY

Science>Physics>Sound>Reflection of Sound

A reflection of sound, arriving at the listener in less than

0.1 s

after the direct sound is called _____.

EASY

Science>Physics>Sound>Reflection of Sound

The method used by some animals like bats, tortoises and dolphins to locate the objects by hearing the echoes of their ultrasonic squeaks is known as _____. (reverberation/echolocation)

EASY

Science>Physics>Sound>Reflection of Sound

_____ wave is used for echo depth sounding.

EASY

Science>Physics>Sound>Reflection of Sound

The multiple reflections of sound in a hall is called _____.

EASY

Science>Physics>Sound>Reflection of Sound

Echoes are caused by the _____ of sound.

EASY

Science>Physics>Sound>Reflection of Sound

The name for a reflected sound is _____.