The energy of the wind can be harnessed to perform many different kinds of work. Your students can make their own pinwheels to see the power of wind at work.
Materials needed (for each pinwheel):
- Thin cardboard—a manila folder works well
- Straightened jumbo paper clip, with one end (about 1.5-cm) bent at a right angle
- Small paper clip
- Masking tape
- Small milk carton
- String (approx. 30 cm long)
- Safety goggles
Note: Students should wear safety goggles when using scissors.
1. Cut out a 15-cm square of thin cardboard. In the center of the square, draw a circle about the size of a quarter.
2. With the ruler, draw lines from each corner of the square toward the center circle, as seen in the diagram. Cut inward from the corners along these lines, stopping at the small circle.
3. Poke 5 small holes in the square where indicated in the diagram and then bend in the cardboard to align the holes.
4. Poke the bent end of the large paper clip through the back side of the pinwheel and tape it securely to the cardboard.
5. Cut the top (folded, spout portion) off the milk carton and poke two small holes into opposite sides of the carton, as seen in the illustration.
6. Slide the long, straight end of the jumbo paper clip through the holes in the carton. Securely tape one end of the string to the end of the paper clip poking out from the far side of the carton. Attach a small paper clip to the other end of the string.
7. Now blow hard on the blades of the pinwheel. What happens?
8. A small pinwheel can lift a paper clip. Discuss with students what other kinds of work wind energy can do.