The theme for this week’s Unplugged Project was weather and the weather today was windy, VERY windy. We decided to try making a homemade anemometer (device that measures wind speed) with the instructions that I found here.
You’ll need some stiff, corrugated cardboard, four small Dixie-type paper cups, a long sharp pencil with eraser, a stapler, scissors, a push pin and some modeling clay.
First cut the small rims off the paper cups using the scissors.
Next cut the cardboard into two strips of equal length. Staple them together in the form of a cross.
Color one cup a different color. Red or something bright would be easier to spot, but all we could find that would work on the waxy surface of the cup was a black Sharpie.
Find the exact center of your cross by drawing an “X” between the corners of the center portion like this:
Where the lines cross is the center and is where you will put your thumb tack. (NOTE: This step is easiest to do before you attach the cups).
Staple a cup to the end of each cardboard strip. Make sure they are all facing the same way and are aligned perpendicular to the cardboard strips.
Push the pin through the center of the cross and into the eraser of the pencil.
Take your anemometer outside and stick it to a porch railing or table in a base made out of modeling clay.
Your anemometer should now spin in the wind! (*SHOULD* – read note below!)
To check the speed, count the number of times the colored cup passes by you in one minute. Obviously the more times it swings by, the faster the wind. You can measure at different times of day to compare the wind speeds.
If you want to get really scientific you can calibrate your anemometer using your car. Read the clever instructions for how to do it here.
* NOTE* – We discovered that although it was a very, very windy day out (55 mph gusts), the gusts were so variable in strength and direction that our anemometer didn’t spin very well (but it did blow off the railing once or twice!).
It worked much better inside with human-generated wind as you can see here in this very primitive video! (PS. Please ignore my messy house):
If you joined in this week’s weather Unplugged Project, please link to your project post (not just your blog – we always want to be able to find your post) in the Linky below. If you didn’t join in the Unplugged Project but think you might like to in the future, read more about how to participate here. We’d love to have you!
The theme for next week’s Unplugged Project will be:
I must be in a “W” phase at the moment. I hope to see you next week!