Aspeaker at an open-air concert emits 700 w of sound power, radiated equally in all directions. earplugs you can buy in the drugstore have a noise reduction rating of 23 decibels.
if you are wearing those earplugs but your friend phil is not, how far from the speaker should phil stand to experience the same loudness as you?
express your answer to two significant figures and include the appropriate units.