1. The problem statement, all variables and given/known data A concert loudspeaker suspended high off the ground emits 28.0W of sound power. A small microphone with a 0.900cm^2 area is 51.0m from the speaker. A) What is I at the microphone? B) How much sound energy impinges on the microphone in J? 2. Relevant equations I = P/A I = 4pir^2 3. The attempt at a solution I have solved the answer to part A): I = 28W/4pi(51)^2 = 8.57*10^-4 W/m^2 The answer to part B is what's eluding me: I know that at the microphone I = 8.57*10^-4 W/m^2 So: 8.57*10^-4 = P/.009m^2 P = 7.713*10^-6 W which is equal to J/s Therefore my answer would be 7.713*10^-6 J of sound energy are impinged each second. Mastering Physics is disagreeing with me. Any advice?