You’re out at the park with some friends where there is an open-air concert. Standing 20. meters from the stage, the music is a agreeably loud 90. dB. After a while you all decide to move somewhere quieter where you can hear each other talk. How far away from the stage must you go so that the music loudness is only 60. dB? You can suppose that the sound waves move uniformly in all directions—don’t worry about reflections off the ground.