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nicholasH
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Homework Statement
A sound source is placed at the top of a tall (h = 189.6m) radio tower. The source has a frequency of 740 Hz and an amplitude of 19.4 nm at point A. The air surrounding the tower has a density of 1.29 kgm-3 and sound travels through it with a velocity of 343 ms-1. Point A is 13.5 m above the source. You may ignore any reflections of the sound from the ground.
Calculate the average power leaving the source.
Homework Equations
P = (1/2)pAv(ws)^2
where p = density of air = 1.29
v = sound velocity = 343
s = maximum displacement (amplitude) = 19.4e-9
w = 2Pi*f = 2960*Pi
A = area of speaker
The Attempt at a Solution
It seems that this question is unsolvable without being supplied with the area of the speaker. Unless the amplitude at Point A somehow depends upon this area, however I'm sure that it depends solely upon the size of the speakers vibrations, not the area of the surface causing them.
Any help would be greatly appreciated.