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November 18, 2002
A: FROM MENTOR MOLLY WILLIAMS
IN MI
Here's another reason: Sometimes, when the wires are in a
windy
location, they will vibrate just like a guitar string. That
puts a
lot of stress on the support towers. In order to prevent that
from
happening, you can add weights or baffles with odd spacings.
Here's
something you can try at home. Make a rudimentary stringed
instrument with a piece of stretched string, wire, or a rubber
band.
Adjust the tension and length until you can get a nice tone
wheen
you pluck it. Then add something to disturb the even weight
distribution, like a few knots in the string, or a few beads.
You'll find you can no longer get a resonance.
November 15, 2002
A: FROM MENTOR CAROL TOMAN
IN IL
I think you noticed red balls, centered between power poles.
These
are simply highly-visible markers placed on wires near airports
so
pilots avoid approaching or departing an airport at too low
an
altitude. The airport might be as small as a private grass
strip on a
farm or ranch. Look around for an orange wind-sock and you'll
see the
landing strip very close by.
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