Answer:
Multiple answers:
1. Power output P=17.59W
2.Intensity 160m I=17.6W/[tex]m^{2}[/tex]
3. dB = 77.3
4. f=178.5 Hz
Explanation:
First one comes from the expression
[tex]I=\frac{P}{4\pi r^{2} }[/tex]
where I is the intensity, P is the power and r is the radio of the spherical wave, or in this case, the distance x. I solved for the Power by multiplying Intensity with the area (4[tex]\pi x^{2}[/tex]
Second one is done with:
[tex]\frac{I_{2} }{I_{1} } =\frac{x^{2}_{1} }{x^{2} _{2}}[/tex]
Solving for Intensity 2, the result mentioned.
The third is simply computed with
[tex]dB=10*log\frac{I}{10^{-12} }[/tex]
And finally the last one is done with doppler effect, taking into account the speed of the air as in 10ºC 337m/s.
[tex]f=f_{initial} *(\frac{s+v_{receiver} }{s+v_{source} } )[/tex]
Where Finitial is the frequency emitted and s is the speed of the sound. The wind blowing in positive is, in principle, going away of the observer.
