Sound intensity of Two sounds

1. Apr 27, 2012

eagles12

1. The problem statement, all variables and given/known data

Sound 1 has an intensity of 39.0 W/m^2. Sound 2 has an intensity level that is 2.5 dB greater than the intensity level of sound 1. What is the intensity of sound 2?

2. Relevant equations

I=energy/area*time
β=(10dB) logI/Io
Io=10^-12 W/m^2

3. The attempt at a solution

Intenisty 1= 39=energy/area*time
β for the second sound= 339.776
Using this i plugged in
339.776=(10dB) logI/Io
33.977=logI/Io
9.49*10^33=I/Io
and found I=9.5*10^21 but it is saying this is incorrect

2. Apr 27, 2012

collinsmark

I'm not following your logic on that. :uhh:

I think you might be making this problem harder than it is. When the problem statement says, "Sound 2 has an intensity level that is 2.5 dB greater than the intensity level of sound 1" that means,

$$2.5 \ \mathrm{dB} = 10 \ \log \frac{I_2}{I_1}$$
where I1 is given as 39.0 W/m2. Solve for I2.