Question

What is the intensity of a sound with a measured intensity level of 84 db? (i0 = 10-12 w/m2)?

Answer 1

The unit measurement for sound can be expressed in terms of intensity and in decibels. The intensity of sound is the measure of its power over unit area. The common unit of measurement is in decibels. This is commonly used in measuring the extent of noise. The conversion from intensity to the decibel unit is through logarithmic function. The formula is:

dB = 10 log(I/I0), where I0 is 10^-12 Watts per square meter

Substituting the values to the equation,

84 = 10log(I/10^-12)
I = 0.0002512 W/m2

In scientific notation the intensity is 2.512 x 10^-4 W/m^2.