You are trying to overhear a juicy conversation, but from your distance of 17.0 m, it sounds like only an average whisper of 35.0 dB. So you decide to move closer to give the conversation a sound level of 80.0 dB instead.

How close should you come?
d= ?? cm

2 answers

halving the distance adds six db. You can use the inverse square law to show that.

halving the distance = 41db
halving again=47db
halving again= 53 db

or (1/2)^n= 6n= 80-35
(1/2)^n=45
2^-n=45

log2 of each side
n=log2 45= 6.7

distance= 17*2^-6.7=.162m or 16.2cm

check my thinking
it didn't end up being correct, but i'm not sure where it goes wrong...