Calculating Distance for Siren Sound Intensity Level

In summary, the sound produced by a siren is a result of vibrations created by its rotating rotor, which travel through the air as sound waves. The pitch of the siren sound changes due to the Doppler effect, and the frequency of the sound can be calculated using a formula. The shape and size of a siren can also affect the sound it produces, along with other factors such as the material and texture of the rotor, rotation speed and direction, and the surrounding environment.
  • #1
yaser1989
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0

Homework Statement



Residents of Hawaii are warned of the approach of a tsunami by sirens mounted on the tops of towers. Suppose a siren produces a sound that has an intensity level of 120 dB at a distance of 2.0m.

Homework Equations



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

The Attempt at a Solution



I calculated I at 2m: I = 1 w/m^2
P at 2m and 1 w/m^2 = 50.26548

I just don't know what values I should use to calculate r.
 
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  • #2
You did not post the actual question. :confused:
 

1. What is the physics behind the sound produced by a siren?

The sound produced by a siren is a result of vibrations created by its rotating rotor. These vibrations travel through the air in the form of sound waves, which are then picked up by our ears.

2. How does the pitch of a siren sound change as it approaches and passes by?

The pitch of a siren sound changes due to the Doppler effect. As the siren approaches, the sound waves are compressed, resulting in a higher pitch. As it passes by and moves away, the sound waves are stretched, resulting in a lower pitch.

3. Can the frequency of a siren sound be calculated?

Yes, the frequency of a siren sound can be calculated using the formula: f = (n * v) / λ, where n is the number of rotations per second, v is the speed of sound, and λ is the wavelength of the sound wave.

4. How does the shape and size of a siren affect the sound it produces?

The shape and size of a siren can affect the sound it produces by changing the wavelength and frequency of the sound waves. A larger siren may produce a lower pitch sound, while a smaller siren may produce a higher pitch sound.

5. What other factors can affect the sound produced by a siren?

Other factors that can affect the sound produced by a siren include the material and texture of the siren's rotor, the speed and direction of the siren's rotation, and any obstructions or reflections of sound waves in the surrounding environment.

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