Frequency and Energy Relation
Name: Margaret T.
Are energy and frequency related? What I mean by this is
can a wave have a high frequency and low energy and if so what does this mean?
Does this mean that since I know that energy and amplitude are
proportional and amplitude and loudness are proportional that a wave can
reach me quickly but be very quite or visa- versa?
This is a tricky question because it depends upon what kind of wave you
mean. The energy of a "classical" sound wave is proportional to the square
of the amplitude, i.e.: E = |A|^2. But at the atomic level that no longer
applies and E = h*f where f is the frequency and h is Planck's constant, but
that is electromagnetic waves at the quantum level. Now back to sound waves.
"Loudness" is different. Loudness is our ear's (and brain's) response to a
sound wave. This does depend on the amplitude of the wave, but it also
depends upon the frequency. And if the sound is not a single frequency, the
"loudness" depends upon the distribution of overtones of the fundamental
(the 'pitch'). All of this "goes out the window" if you now mean a sonic
boom, because now the "wave" is traveling faster than the speed of sound and
the same physics does not apply. So the "answer" to your question has a lot
of "ifs" attached.
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Update: June 2012