From: Holt, Rinehart and Winston

Pilots at the Fly Away Airport need your help -- fast! Last night, lightning destroyed the orange windsock. This windsock helped pilots measure which direction the wind was blowing. But now the windsock is gone with the wind, and an incoming airplane needs to land. The pilot must know what direction the wind is blowing and is counting on you to make a device that can measure wind direction.

Materials: paper plate, drawing compass, metric ruler, protractor, index card, scissors, stapler, plastic straw, sharpened pencil, pushpin, magnetic compass, small rock

Ask a question
1. How can I measure wind direction?

Conduct an experiment
2. Find the center of the plate by tracing around its edge with a drawing compass. The pointed end of the compass should poke a small hole in the center of the plate.
3. Use a ruler to draw a line across the center of the plate.
4. Use a protractor to help you draw a second line through the center of the plate. This new line should be at a ninety degree angle to the line you drew in Step 3.
5. Moving clockwise, label each line N,E, S and W.
6. Use a protractor to help you draw two more lines through the center of the plate. These lines should be at a 45 degree angle to the line you drew in steps 3 and 4.
7. Moving clockwise from N, label these new lines NE, SE, SW and NW. The plate now resembles the face of a magnetic compass. This will be the base of your wind-direction indicator. It will help you read the direction of the wind at a glance.
8. Measure and mark a 5 x 5 cm square on an index card. Cut the square out of the card. Fold the square in half to form a triangle.
9. Staple an open edge of the triangle to the straw so that one point of the triangle touches the end of the straw.
10. Hold the pencil at a 90 degree angle to the straw. The eraser should touch the balance point of the straw. Push a thumbtack or pushpin through the straw and into the eraser. The straw should spin without falling off.
11. Find a suitable area outside to measure the wind direction. The area should be clear of trees and buildings.
12. Press the sharpened end of the pencil through the center hole of the plate and into the ground. The labels on your paper plate should be facing the sky.
13. Use a compass to find magnetic north. Rotate the plate so that the N on the plate points north. Place a small rock on top of the plate so that it does not turn.
14. Watch the straw as it rotates. The triangle will point in the direction the wind is blowing.

Analyze the results
15. From what direction is the wind coming?
16. In what direction is the wind blowing?

Draw conclusions
17. Would this be an effective way for pilots to measure wind direction? Why or why not?
18. What improvements would you suggest to Fly Away Airport to measure wind direction more accurately?