A certain source of sound waves radiates uniformly in all directions. At a distance of 14 m from the source the intensity level is 67 db. What is the total acoustic power output of the source, in watts? (Note: The reference intensity I 0 is 1.0 × 10-12 W/m2.)

Respuesta :

Explanation:

It is given that,

At a of 14 m from the source the intensity level is 67 db. We need to find the total acoustic power output of the source. The intensity level is given by :

[tex]B=10\ dBlog(\dfrac{I}{I_o})[/tex]

[tex]I_o=10^{-12}\ W/m^2[/tex] (reference intensity)

[tex]67\ dB=10\ dBlog(\dfrac{I}{I_o})[/tex]

[tex]6.7=\ dBlog(\dfrac{I}{10^{-12}})[/tex]

[tex]I=0.00000501\ W/m^2[/tex]

or

[tex]I=5.01\times 10^{-6}\ W/m^2[/tex]

Output power is given by :

[tex]I=\dfrac{P}{A}[/tex]

[tex]P=I\times 4\pi r^2[/tex]

[tex]P=5.01\times 10^{-6}\times 4\pi (14)^2[/tex]

P = 0.0123 watts

So, the output power of the source is 0.0123 watts. Hence, this is the required solution.

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