You are trying to overhear a most interesting conversation, but from your distance of 10.0m , it sounds like only an average whisper of 20.0dB . So you decide to move closer to give the conversation a sound level of 60.0dB instead. How close should you come?
What intensity I_1 corresponds to 20.0dB?
Using this equation
I = I_0*10^(B/10)
Help I don’t know where to plug things into.
Sound level L1 = 20 dB at a distance r1 = 10 m.
Louder sound level L2 = 60 dB at a closer distance r2 = ? m.
L2 − L1 = 60 dB − 20 dB = 40 dB
r2 = r1 / 10^[(L2−L1)/20] = 10 m / 10^[40/20] = 10 m / 100 = 0.1 m
r2 = 0.1 m = 10 cm.
You should come as close as r2 = 10 cm to listen at a sound level of L2 = 60 dB.
Help: “Damping of sound level vs. distance”:
Use the second calculator.