Sound intensity using decibel values

AI Thread Summary
The discussion revolves around calculating sound intensity from given decibel values using the equation β = 10 log(I2/I1), where I1 is 1.0x10^-12 W/m^2. The user is struggling to derive the correct sound intensity values for 100 dB and 55 dB, which are stated in the textbook as 0.10 W/m^2 and 3.2x10^-7 W/m^2, respectively. Despite substituting the values into the equation, the user is unsure of the next steps to isolate I2. Other participants encourage providing detailed calculations and checking the accuracy of the textbook answers. The conversation emphasizes the importance of step-by-step problem-solving in physics.
123helpme
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okay so I am having trouble with my sound ISU (independent study unit). Though my teacher said he would help, when i asked he said he cant...

what i need to find is the sound intensity for the following decibel values..
a) 100dB
b) 55dB

now the only relevant equation would be \beta= 10 log (I_{}2/I_{}1)
and I_{}1=1.0x10^-12 W/m^2

i have attempted multiple times but can't seem to come to the correct answer
the textbook gave the answers but no solution
a)0.10 W/m^2
b) 3.2x10^-7 W/m^2

a) what i tried was subsituting \beta for 100dB and I_{}1=1.0x10^-12 W/m^2
but from there I am not quite sure what to do

help me please!
 
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You'll need to post more details. What answers are you getting? What did you try? Show step-by-step. Also, check that you copied the book answer correctly for (a).

-Kerry
 
Welcome to Physics Forums.
123helpme said:
a) what i tried was subsituting \beta for 100dB and I_{}1=1.0x10^-12 W/m^2
but from there I am not quite sure what to do

help me please!
You're on the right track. Can you post the equation you get when you make that substitution? You are trying to find I2 in the equation.
 

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