The intensity level of sound 20 m from a jet airliner is 120 dB. At what distance fro mthe airplane will the sound intensity level be a tolerable 100 dB? (Assume spherical spreading of sound.)
2006-11-27 05:31:51 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Physics
20m : 120dB
x : 100dB
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x=20m*100dB/120dB
x=16.66 m
2006-11-27 05:36:31 · answer #1 · answered by CosmicLove 5 · 0⤊ 2⤋
Since a change from 120 db to 100 db represents a lowering in intensity by a factor of 100 and since intensity goes down by a factor of 1 over D squared (D is distance), I would need to be the square root of 100 farther away. 200m should be the answer.
2006-11-27 05:44:55 · answer #2 · answered by Gene 7 · 0⤊ 0⤋
from the formula of the sound intensity, find Intensity 1 and Intensity 2. Find the raport of them, it should be 10^-2. We know that for 10 m of distance, the intensity changes of 100 watt/m^2. So, we must go 10 meters away.
2006-11-27 05:50:42 · answer #3 · answered by Genadi 2 · 1⤊ 0⤋