Answer
$I = 10^{-5} \frac{W}{m^2}$
Work Step by Step
Given the decibel equation $B = 10 \log \frac{I}{I_{0}}$
with $I_{0} = 10^{-12} \frac{W}{m^2}$
Given the decibel level of a hair dryer at $B = 70dB$
Find the sound intensity
$70 = 10 \log \frac{I}{10^{-12}}$
$7 = \log \frac{I}{10^{-12}}$
$10^7 = \frac{I}{10^{-12}}$
$I = 10^{-5} \frac{W}{m^2}$
