Meteorologists use anemometers to measure wind speed in one area. With
this data, they can determine how quickly a storm, or weather system,
will travel to other areas.
Build Your Own Weather Tool!
Use the materials and follow the directions below.
Five 3-ounce paper cups
One straight pin
Pencil (with eraser)
Two straight plastic straws
Watch with a second hand
- Punch one hole in each of four paper cups, about ½" below
the rim. Color the outside of one of the cups.
- In the fifth cup, punch four evenly spaced holes about ¼ "
below the rim.
- Push a straw through the hole of the colored cup. Fold down the tip
of the straw inside the cup, and staple it to the cup on the side opposite
- Push the straw through two opposite holes in the four-hole cup. Attach
another cup to the opposite end of the straw. Make sure that the second
cup faces the opposite direction from the first cup.
- Repeat the above step with the other two cups and straw.
- Position the four cups so that they face the same direction
clockwise or counterclockwise. Make sure the cups are all the same distance
from the center.
- Poke a hole in the bottom of the center cup. Push the eraser end
of the pencil through the hole.
- Push the pin through the intersection of the two straws. Then push
it into the eraser as far as possible.
- With a friend, take the anemometer outside to an open area where the
wind is blowing.
- While one of you times exactly one minute on the watch, the other
counts how many times the colored cup goes by in one minute. This is
the number of revolutions per minute (RPM).
- Convert your answer for RPM to miles per hour (MPH) using this formula:
RPM X 0.2142 = MPH
- Record this number on your Weather
Data Sheet (PDF).
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