Calculating Sound Levels in dB: How to Convert Intensity to Decibels

[RedPhoenix]

Homework Statement

Calculate the sound level in decibels of a sound wave that has an intensity of 4.00u "W/m2.

Homework Equations

dB = 10log(I/Io)

The Attempt at a Solution

dB = 10log(4/1E-12) = 126.02 db

Book says 66db. It vaguely covers this topic, not sure if I had missed something or not.

 

[ideasrule]

That's 4.00 micro-watts per meter squared, or 4.00 * 10^-6 W/m^2. It isn't 4 W/m^2..

 

[RedPhoenix]

That's 4.00 micro-watts per meter squared, or 4.00 * 10^-6 W/m^2. It isn't 4 W/m^2..

pft... I completely overlooked that. Its getting late!