CALCULATING WIND SPEED
Wind speed can be measured using an anemometer. A simple anemometer catches the wind. Depending on
how forceful the wind is the device may be calibrated.
Design your own device which will be used to measure wind speed. Use the information in the diagrams
below for ideas. For each of the devices consider how the wind is caught and how this is used to give
1. Revolving coffee cups 2. Swinging shoe box
lidded box such
hole foam cups as a shoe box
glued onto plate
nail viewing slot
Calibrate the scale by experimenting and
Count the number of revolutions in a set time. comparing to the Beaufort scale.
wood (ruler) thumb tack spirit level (corked
3. Blowing ball test tube with air
a. Face the device into the main wind direction.
b. Make sure the device is level.
c. Take measurements over a two-minute period. protractor
d. Average minimum and maximum angle readings.
e. Use the table below to find the wind speed. fishing line
ping pong ball
Angle 90º 85º 80º 75º 70º 65º 60º 55º 50º 45º 40º 35º
miles/h 0 5.8 8.2 10.1 11 13.4 14.9 16.4 18 19.6 21.4 23.4
km/h 0 9.3 13 16.3 19 21.1 24 26.4 29 31.5 34.4 37.6
m/sec 0 2.6 3.7 4.5 5.3 5.9 6.7 7.3 8.1 8.8 9.6 10.4
Name of device How is the wind caught? How is the wind measured?
1. Revolving coffee cups
2. Swinging shoe box
3. Blowing ball
4. Your Device
AIRWATCH - make the link