A small omnidirectional stereo speaker produces waves in all directions that have an intensity of 8.50W/m2 at a distance of 4.00m from the speaker.
Part A: At what rate does this speaker produce energy?
Part B: What is the intensity of this sound 9.00m from the speaker?
Part C: What is the total amount of energy received each second by the walls (including windows and doors) of the room in which this speaker is located?