# A small omni directional source of noisy sound emits uniformly with a power of 40W. Determine the...

## Question:

A small omni directional source of noisy sound emits uniformly with a power of 40W. Determine the distance from the source for which the sound level is 90 dB. Calculate also the intensity level at a point 100 m from the source. (if there is no absorption)

## Loudness of Sound:

The Loudness of sound is the measurement of its intensity. The minimum audible intensity of sound is {eq}I_0=10^{-12}\ W/m^2 {/eq} if {eq}I {/eq} be the intensity of a sound, then the loudness of the sound in the units of decibel is given by

{eq}L=10\log{\dfrac{I}{I_0}} {/eq}

## Answer and Explanation: 1

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Power of source, {eq}P=40\ W \\ {/eq}

Loudness, {eq}L=90\ dB {/eq}

Distance from source, {eq}r=100\ m {/eq}

We know that

{eq}L=10\l...

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Chapter 6 / Lesson 42Sound is a form of energy that moves through the air. Discover how sound travels as a wave, understand how changes to the wave create sound's loudness and pitch, and explore how different surfaces and materials affect sound, creating echoes and distortion.

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