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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...

Jan 9, 2015



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...

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]. Answer:  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.

Jan 16, 2015

#### What is the difference between intensity and loudness?



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

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

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...

Mar 6, 2015



SONAR

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
...

Feb 27, 2014