A loudspeaker produces a musical sound by means of the oscillation of a diaphragm whose amplitude is limited to 0.9 µm.
At what frequency is the magnitude a of the diaphragm's acceleration equal to g?
[tex]a=-\omega^2 x_m \cos(\omega t +\phi)[/tex]
The Attempt at a Solution
I decided to chuck the cosine term overboard to see what happened... and I got the right answer (525.45 Hz)! Why am I allowed to maximize the cosine term if I'm not told that the diaphragm is constructed to maximize efficiency?