Get a free home demo of LearnNext

Available for CBSE, ICSE and State Board syllabus.
Call our LearnNext Expert on 1800 419 1234 (tollfree)
OR submit details below for a call back

What people are asking?

Asked by Raaunak

Feb 7, 2015

What is the difference between echo and reverberation?


If we shout or clap, near a tall building or a hill, we will hear the same sound back in a little time. This is called an echo.
A sound created in a big hall will persist by repeat...

Answer (3)


Jan 9, 2015

Formulas of sound chapter......

This answer has an image. Please click on the question to read more.

Answer (2)

Asked by Ritik Ranjan

Mar 1, 2015

Working of human ear.


    The pinna collects the sound waves from the surroundings and sends it to ear canal. The ear canal sends the sound waves to the ear drum and s...

Answer (3)

Asked by Shriya Sanjay Patil

Mar 5, 2014

Prove that for hearing distinct echo, minimum distance of the obstacle from source of sound must be 17.2m at 22 Celsius in air [given speed of sound 344m/s].
As the sensation of sound persists in our brain for about 0.1 s, to hear a distinct echo the time interval between the original sound and the reflected one must be at least 0.1s. If we take the speed of sound to be 344 m/s at a given temperature, say at 22 ºC in air, sound must go to the obstacle and reach back the ear of the listener on reflection after 0.1s.
Hence, the total distance covered by the sound from the point of generation to the reflecting surface and back should be at least (344 m/s) ×0.1 s = 34.4 m. Thus, for hearing distinct echoes, the minimum distance of the obstacle from the source of sound must be half of this distance. I.e., 34.4/2 = 17.2 m
[given speed of sound 344m/s]


    17.2 m at room temperature and normal humidity.       

Answer (4)

Asked by Masih

Jan 16, 2015

What is the difference between intensity and loudness?

The sound intensity (acoustic intensity) is defined as the sound power per unit area.

The S.I. unit of intensity: Watt /m2

Answer (2)

Asked by Rushin Naik

Mar 1, 2015

A Stone is dropped into a well 44 meter deep and the sound of splash is heard after 3.12 sec. Find the speed of sound in air.

Time taken by the stone to reach the water surface  can be calculated using the equation of motio...

Answer (2)

Asked by Adithyan Sanal

Mar 6, 2015

What is SONAR? How does it work?


Answer (2)

Asked by Alpha

Feb 17, 2015

A stone is dropped into a well 44.1 m deep. The sound of the splash is heard 3.13 seconds after the stone is dropped. Find the velocity of sound in air. (g = 9.8 m/s²).

Time taken by the stone to reach the water surface  can be calculated using the equation of motion
s = ut + ½ gt2
Here u = 0, s = 44.1 m , g = 9.8 m/s2

Answer (1)

Asked by Ravinder Ghanghas

Feb 27, 2014

state 2 conditions for echo to be heard . bats cannot see still they catch their prey . explain

Answer (5)

Asked by Neha Sony

Nov 27, 2014

what  is reverberation ?

Many multiple echoes of a sound can be produced are called as reverberations.
Reverberation is the phenomenon of overlapping of sound caused by multiple reflections...

Answer (1)