Anemometer is an instrument for measuring the speed of the wind. You need only 15-30 minutes to make it. Anemometers can be quite different: the ones which are described in this article, and the devices which cost hundreds of thousands of rubles, which are used to make the forecast.
Steps:
1. Take five paper cups and do the holes in each of them, so that you can thread the straw through it. Two cups should be held at the same level. Do the same with the other two cups.
2. Stick a pencil into the fifth cup and the straws, in the center. The puncture should be made exactly in the middle, so take your time. The pencil acts as a nail, and the fifth cup as a supporting tube.
3. Fix the cups on the straws, using quick-drying glue or adhesive tape. Normal tape will not work.
4. Check the anemometer, by blowing on it. If any of the cups is not fixed securely, fix it and try again.
5. Done!