A rock group is playing in a bar. Sound
emerging from the door spreads uniformly in
all directions. The intensity level of the music
is 116 dB at a distance of 5.77 m from the
At what distance is the music just barely
audible to a person with a normal threshold
of hearing? Disregard absorption.
Answer in units of m.
I1(dB) (the intensity level 5.77 meters from the door)=116 dB
r1 (distance from door when intensity is 116 dB)= 5.77 m
Io (Intensity at threshold of hearing)= 1e-12
r2 (Radius at threshold of hearing)
P (power of sound source)
I1(w/m^2) (intensity 5.77 meters from door in watts/meters squared)
The Attempt at a Solution
First, I changed the given Intensity into W/m^2 instead of hertz.
So that's the Intensity at the spot from the door mentioned, so now I calculated the power source.
So, now that I had the power source, I calculated the radius needed to achieve threshold of hearing
Doesn't seem right... 3.6 million miles seems overkill.