Reflection of Sound

A person burned a firecracker in front of a cliff and heard its echo $5 \mathrm{s}$ after it burst. The distance of the cliff from the person, if the speed of the sound is $340 \mathrm{m}/\mathrm{s}$, is close to

Which property of sound is made use of in designing sound proof chambers?

Echoes are used to measure _____.

How does echo help us in ocean navigation?

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

(Speed of sound is $346 \mathrm{m} {\mathrm{s}}^{-1}$) 

If the velocity of sound in air is $340 \mathrm{m} {\mathrm{s}}^{-1}$ and $x$ is the minimum distance between sound source and reflecting surface to get echo from general sound, then :

(i). Does sound follow the same law of reflection as light? Explain.
(ii). List two practical applications for sound wave reflection.
(iii). A stone is dropped from the top of a tower $500\mathrm{m}$ high into a pond of water at the base of the tower. When is the splash heard at the top? Given, (i).(i).$g=10{\mathrm{ms}}^{-2}$ and speed of sound is $340{\mathrm{ms}}^{-1}$.

Explain the term "echo." Maintain the same distance between the reflecting surface and the sound-producing source. On a hotter day, can you hear the echo?

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?

Give two examples of good absorbers of sound.

Give two examples of good reflectors of sound.

Walls of auditorium should be

In question 93, if Suresh were standing unsymmetrically between parallel cliffs, the distance between two cliffs is

Suresh standing symmetrically between two cliffs claps his hands and starts hearing a series of echoes at intervals of 1 second. If speed of sound in air is 340 m/s, the distance between the parallel cliffs must be

SONAR is based on the principle of

Echo is produced due to

The persistence of hearing for human beings is not more than

Soft materials are better than hard materials for muffling sound.

_____ wave is used for echo depth sounding.

An observer stands at a distance of $850 \mathrm{m}$ from a cliff and fires a gun. After $k \mathrm{seconds}$ he hears an echo. Calculate the value of $k$, if the speed of sound in air is $340 \mathrm{m} {\mathrm{s}}^{-1}$.