# A certain source of sound waves radiates uniformly in all directions. At a distance of 20 m from...

## Question:

A certain source of sound waves radiates uniformly in all directions. At a distance of 20 m from the source, the intensity level is 51 dB.

a) What is the intensity (in {eq}W/m^2 {/eq}) of the sound waves at that distance from the source? (Note: The reference intensity {eq}I0 {/eq} is {eq}1.0 \times 10^{-12}\ W/m^2 {/eq}.)

b) What is the total acoustic power output of the source, in watts?

## Sound Intensity Level:

Sound intensity levels denote a given sound wave's sound intensity in terms of decibels (dB). The sound intensity level (SIL) is the basis of the loudness of a sound. The SIL is a function of the intensity of the wave itself, and it can be determined as:

{eq}\displaystyle \rm \beta = 10log_{10} \left(\frac{I}{1\ \times\ 10^{-12}\ W/m^2}\right) {/eq}

where:

- {eq}\displaystyle \rm I {/eq} is the intensity of the sound

## Answer and Explanation: 1

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Given:

- {eq}\displaystyle r = 20\ m {/eq} is the distance from the source

- {eq}\displaystyle \beta = 51\ dB {/eq} is the sound intensity level

- {eq}...

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Chapter 5 / Lesson 10This lesson explains what wave intensity in physics is, and it explains the intensity of light formula with examples. This lesson also describes how to calculate intensity of sound waves.

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