# Physics

posted by on .

Hi I am absolutely stumped on this question.

A loudspeaker is placed between two observers who are 110 m apart, along the line connecting them. If one observer records a sound level of 60.1 dB and the other records a sound level of 74.9 dB, how far is the speaker from each observer?

What I did for this is

I found the the Intensities of both the sound levels.
Then using the formula r1= SQRT(I2/I1)*R2

I would solve for r1 and then do r1+r2=113 to find r2.

I also don't know what value to assign for I2 and I1, i tried both ways but its wrong.

• Physics - ,

This is the fourth time you have posted this question, which has already been answered. Please stop

• Physics - ,

There was a typo error in my previous answer, which you noticed. The final answer is the same.

In calculating the intensity ratio, I meant to write 10^1.48 = 30.2. Sorry about the typo in the exponent. The 30.2 is correct. 1.48 is 1/10 of the dB difference in received sound levels.

If it is a mystery where the 10^(0.1*dB difference)comes from, that is the definition of decibels in terms of intensity ratio

Log10(I2/I1) = 1/10 (dB2 - dB1)

10^[0.1(dB2-dB1)] = I2/I1