Finding intensity and sound level from a source...?

Question

The source of a sound wave has a power of 1.00 μW. If it is a point source, (a) what is the intensity 3.00 m away and (b) what is the sound level in decibels at that distance?

Explain your work. Thanks! :)

Answer 1

The intensity (power/area) is 1 μW/area of 3-m radius sphere = 1 μW/(4pi*3^2). Units are W/m^2.
The dB sound level = 10*log-base-10(intensity/1E-12 W/m^2).