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Wind Speed
Moving air is called wind. Meteorologists
are interested in how fast the wind is moving.
To measure wind speed, meteorologists use
anemometers
and
wind meters
. An
anemometer uses a rotating
shaft
with wind-
catching cups attached at the top. The harder
the wind blows, the faster the shaft rotates,
and the faster the cups move through the air.
The moving cups measure the wind speed.
A wind meter is an instrument with a small
ball in a tube. When wind blows across the
top of the tube, the flow of air up the tube
lifts the ball. The harder the wind blows, the
higher the ball rises. Both instruments are
adjusted to report wind in miles per hour
(mph) or kilometers (km) per hour.
An anemometer
A wind meter
Plants and flags can show the
direction the wind is blowing.
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