13.35.
The maximum speed of the speaker occurs at the equillibrium location,
when all the energy in the spring connected to the speaker is in
kinetic energy. There,
Solving for vmax, we find
So, the frequencies heard range from
to
where v is the speed of sound.
Plugging in the numbers, we find that
f'min = (440 Hz)(.997)
f'min = 439 Hz
f'max = (440 Hz)(1.003)
f'max = 441 Hz