Sound Intensity and Sound Level

In summary, the intensity of sound from a certain source is measured at two points separated by 11.8m. The sound level is 68.10 dB at the first point and 60.31 dB at the second point. Using the equations SL = 10log(I/Io) and I = P/(4pi*r^2), we can find the values of I(1) and I(2). Setting these equations equal to each other and solving for r yields a value that is incorrect.
  • #1
leinad0213
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0

Homework Statement



The intensity of the sound from a certain source is measured at two points along a line from the source. The points are separated by 11.8 m, the sound level is 68.10 dB at the first point and 60.31 dB at the second point. How far is the source from the first point?

d = 11.8m
SL1 = 68.1dB
SL2 = 60.31dB

Homework Equations



SL = 10log(I/Io)
I = P/(4pi*r^2)

The Attempt at a Solution



Find I(1) and I(2)

I(1) = Io*10^(68.1/10) = 6.46*10^-6 = P/(4pi*r1^2)
I(2) = Io*10^(60.31/10) = 1.07*10^-6 = P/(4pi*(r1+d)^2)

So I set the two equations to I(1)/I(2) = (r1+d)^2/r1^2 = 6.04

When I solve for r1, the answer turns out wrong. I am fairly certain this is the approach I am supposed to take.
 
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  • #2
What value do you get for r?
 

1. What is sound intensity and how is it measured?

Sound intensity is the amount of energy that passes through a unit area per unit time. It is measured in units of watts per square meter (W/m^2). Sound intensity can be measured using a sound level meter, which measures the pressure variations in the air caused by sound waves.

2. How is sound level different from sound intensity?

Sound level is a logarithmic measure of the sound intensity and is expressed in decibels (dB). It is a more practical way to describe the loudness of sound as it takes into account the sensitivity of human hearing. Sound level is also commonly used to compare different sound sources.

3. What is the relationship between sound intensity and sound level?

The relationship between sound intensity and sound level is logarithmic. This means that a small change in sound intensity can result in a large change in sound level. The formula for calculating sound level from sound intensity is L = 10log(I/I0), where L is the sound level in decibels, I is the sound intensity, and I0 is the reference intensity of 10^-12 W/m^2.

4. Can sound level be harmful?

Yes, sound level can be harmful to human health if it exceeds certain levels. Prolonged exposure to sound levels above 85 dB can cause hearing damage. The threshold for pain is around 120 dB. It is important to protect our ears from high sound levels and to limit our exposure to loud noises.

5. How can sound level be controlled or reduced?

There are several ways to control or reduce sound levels. This can include using sound-absorbing materials, such as acoustic panels, to reduce the reflections of sound waves. Sound barriers can also be used to block sound from reaching certain areas. Additionally, using earplugs or earmuffs can protect individuals from harmful sound levels. In some cases, sound levels can also be controlled by adjusting the source of the sound, such as turning down the volume on a speaker or moving away from the source of the sound.

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