- #1
Malavin
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Homework Statement
A certain loudspeaker system emits sound isotropically with a frequency of 1770 Hz and an intensity of 0.892 mW/m2 at a distance of 5.66 m. Assume that there are no reflections. (a) What is the intensity (in mW/m2) at 30.8 m? At 5.66 m, what are (b) the displacement amplitude and (c) the pressure amplitude of the sound? Take the speed of sound to be 343 m/s and the density of air to be 1.21 kg/m3.
I mostly need help with part b, I believe I can get part c with the answer from part b.
Homework Equations
I = 1/2(ρvω2sm2)
The Attempt at a Solution
So, for part b and from the relevant equation:
sm = (2I/ρvω2)1/2
ω = 2πf = 2*3.14159*1770 = 11121.24 Hz
So, using the above equation and plugging in I = 0.892 mW/m2, ρ = 1.21 kg/m2, and v = 343 m/s, I get the answer 5.895 x 10-6 m. However, this answer is apparently wrong, and I'm not sure why. Is there something wrong with my calculations?
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