A concert loudspeaker suspended high off the ground emits 35 W of sound power. A small

microphone with a 1.0 cm2 area is 50 m from the speaker.
(a) What is the sound intensity at the position of the microphone?
(b) How much sound energy impinges on the microphone each second?

1 answer

a) is a standard formula

b) what is the surface area at 50m

Area= 4PI(50)^2

area of mike= 1cm^2*=(1m/100cm)^2=1E-4m^2

sound energy=35*1E-4/4PI2500