A rock group is playing in a bar. Sound emerging from the door spreads uniformly in all directions. The intensity level of the music is 115 dB at a distance of 3.58 m from the door. At what distance is the music just barely audible to a person with a normal threshold of hearing? Disregard absorption. Answer in units of m.

How do motion-sensing input devices like accelerometers and gyroscopes work, and where are they commonly used?

1) The intensity of the sound coming from a piece of machinery was measured 1.2 m from the machine and found to be 115 dB. What is the intensity for someone 10 ft away from the machine? 2) What is audiometric testing? What, if anything, does it have to do with hearing conservation programs?