the threshold of hearing is defined as the minimum discernible intensity of the sound. it is approximately 10−12w/m2 . find the
distance d from the car at which the sound from the stereo can still be discerned. assume that the windows are rolled down and that each speaker actually produces 0.06 w of sound, as suggested in the last follow-up comment.
The power carried by sound waves per unit area in the direction perpendicular to that region is known as sound intensity or acoustic intensity. The watt per square meter (W/m2) is the SI unit of intensity, which also covers sound intensity. Sound intensity is a measure of how quickly energy moves across a given space. The unit area in the SI measurement system is 1 m2. So Watts per square meter are used to measure sound intensity. As there will be energy flow in certain directions but not in others, sound intensity also provides a measure of direction.
