Given :
The decibel scale intensity for busy traffic is 80 dB.
Two people having a loud conversation have a decibel intensity of 70 dB.
To Find :
The approximate combined sound intensity.
Solution :
We know, intensity in decibel can be converted to W/m² by :
[tex]\beta(dB) = 10\ log_{10}( \dfrac{I}{I_o})[/tex]
Putting intensity in decibel scale, we get :
[tex]I(80\ dB ) =10^{-4}\ W/m^2\\\\I(70\ dB ) = 10^{-5}\ W/m^2[/tex]
Let, combine intensity is I .
I = I(80 dB) + I(70 dB)
[tex]I = 10^{-4} + 10^{-5} \ W/m^2\\\\I = 1.1 \times 10^{-4} \ W/m^2[/tex]
Therefore, the combined sound intensity is [tex]1.1 \times 10^{-4} \ W/m^2[/tex] .