Determine the sound power level of the compressor

[2idle]

A compressor installed in a large factory radiates sound uniformly. its sound pressure level at 45m away is measured as 68dB.

Determine (a) the sound power level of the compressor
(b) the power output of the compressor

 

[berkeman]

A compressor installed in a large factory radiates sound uniformly. its sound pressure level at 45m away is measured as 68dB.

Determine (a) the sound power level of the compressor
(b) the power output of the compressor

Welcome to the PF. You must show us your own work and thoughts, as well as the relevant equations, before we can offer any tutorial help. How would you approach this problem?

 

[2idle]

OK You've rumbled me, however I'm by no means after a fast easy way to complete an assignment as I've spent the last 6 hours on this question.
There was a third part to the question but I'm feeling quite confident about this
the third part was, determine the expected sound prssure level at 10m and 100m from the compressor.

To complete this part I used the formula -- L2 = L1-20log r2/r1

Where L2 is the new sound level at the new distance
L1 is the sound level at the reference distance
r1 is the reference distance from the source
r2 is the new distance from the source

 

[berkeman]

What is the difference between "sound pressure level" at a distance, and the "sound power level of the compressor"? I'm not that familiar with the terms, so if you could show us the defining equations, that will help. And what units is the "68dB" number in? dB what?