Answer:
(a). The total sound intensity [tex]4.16\times10^{-5}[/tex].
(b). The combined sound level 76.19 dB.
Explanation:
Given that,
Sound level = 75.0 dB
We need to calculate the noise
Using formula of intensity
[tex]I=I_{0}\ 10^{\frac{\beta}{10}}[/tex]
Put the value into the formula
[tex]I_{n}=10^{-12}\times10^{\dfrac{75.0}{10}}[/tex]
[tex]I_{n}=0.0000316= 3.16\times10^{-5}[/tex]
We need to calculate the sound intensity
[tex]I_{s}=10^{-12}\times10^{\dfrac{70.0}{10}}[/tex]
[tex]I_{s}=0.00001=1.0\times10^{-5}[/tex]
(a). We need to calculate the total sound intensity
The total sound intensity
[tex]I=I_{n}+I_{s}[/tex]
[tex]I=3.16\times10^{-5}+1.0\times10^{-5}[/tex]
[tex]I=4.16\times10^{-5}\ dB[/tex]
(b). We need to calculate the combined sound level
Using formula of sound level
[tex]sound\ level =10 log(\dfrac{I}{I_{0}})[/tex]
[tex]sound\ level =10 log(\dfrac{4.16\times10^{-5}}{10^{-12}})[/tex]
[tex]sound\ level=76.19\ dB[/tex]
Hence, (a). The total sound intensity [tex]4.16\times10^{-5}[/tex].
(b). The combined sound level 76.19 dB.