This video will show you how to build an anemometer,
a device used to measure wind speed, out of simple household materials. To build your anemometer, you will need two
straws, a pencil with an eraser on the end, five three ounce paper cups, a pushpin, and
a hole puncher. Start by using the hole puncher to punch four
holes opposite each other just below the rim of one of the cups. Then push the two straws through these holes. Use the hole puncher to punch two adjacent
holes in each remaining cup. Thread each of these cups onto the ends of
the straws through the two holes. Make sure the cups all face the same direction
around a circle, meaning they all face clockwise or all counter-clockwise. If one of the cups is backwards, then your
anemometer will not work. Next, use the tip of a sharpened pencil to
poke a hole in the bottom of the center cup. Press the pencil through the hole eraser first,
and wiggle it slightly to widen the hole so the pencil can rotate easily. Lightly press a pushpin through the two straws
and into the eraser. Do not push it in too far, or this will create
too much friction, and your anemometer will not rotate. Stand your anemometer up on end and try giving
it a spin. If it doesn’t spin, try loosening the pushpin
to reduce the amount of friction. Now, hold the anemometer up in front of a
fan or take it outside on a windy day. Observe how fast it spins when the wind speed
changes. To see written instructions for a science
project and classroom lesson plan you can do using the anemometer, visit the links at
the end of this video. To see thousands of other science and engineering
projects, visit us online at www.sciencebuddies.org.