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Old January 24th 08, 01:13 AM posted to rec.radio.amateur.antenna
Mike Monett Mike Monett is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 23
Default Where's the energy? (long)

"Tom Donaly" wrote:

[...]

Most undergraduate physics texts have, or should have, discussions
of vibrating strings. There's a good treatment of the subject in
William C. Elmore's and Mark A. Heald's book _Physics of Waves_
published by Dover.


If you wanted to get in an argument you could say that the energy
on both sides of the node isn't traveling, but is merely
alternating between potential and kinetic.


Yes, I thought about that a bit before posting. It seems logical a
plucked string sends a wave in both directions, where it is
reflected and returns to create a standing wave.

When it forms a standing wave, it seems reasonable to say the energy
is alternating between potential and kinetic. But isn't that similar
to what happens on a transmission line that is exactly some multiple
of a quarter wavelength long?

Such strings have loss (or you wouldn't be able to hear them).


Loss is a taboo subject on this newsgroup because it makes wave
behavior too hard to understand for the savants posting here.


73,
Tom Donaly, KA6RUH


Regards,

Mike Monett