<PRE><B>Question 79520</B>
The decibel level of sound is given by D=10log(I/10^-12), where I is the sound intensity measured in watts per square meter. Find the decibel level of a whisper at an intensity of 5.4*10^-10 watts per square meter.
:
Substitute 5.4(10^-10) for I in the given formula:
:
D = 10*log({{{((5.4(10^-10)))/((10^-12))}}})
:
D = 10*log({{{5.4(10^-10)(10^12)}}})
:
D = 10*log({{{5.4(10^2)}}})
:
D = 10*log(540)
:
D = 10*2.7324
:
D = 27.32 decibel level of a whisper </PRE>