Science teachers must take complicated scientific theories and experiments and make them accessible to children of all ages, a task that is not always easy. One way that teachers get students to connect to material is through the hands-on approach, allowing them to interact with science in a tangible way. A common project for studying meteorology involves building whirligigs and weather vanes, which measure wind direction and speed.
Strip the wrappers from both of your soda bottles. The size of soda bottle you use does not matter, as long as they are all the same size. Cut the tops off of both bottles, so that you have two open cylinders.
Draw eight lines vertically down one of the bottles, spacing them out as equally as possible around the bottle. The distance between the lines will vary depending on the size of soda bottle you have.
Cut along the lines you just drew, working from the top. Leave one inch of space at the bottom of the bottle uncut, so that you have flaps hanging off of the bottom of the bottle.
Turn the bottle so that the bottom faces up. Use a sharp nail to poke a hole through the bottom-center of the bottle. Repeat with the other bottle as well, so that each bottle has a hole in the bottom-center.
Bend the flaps of the cut bottle backwards, so that they stretch outwards like fan blades. Insert the uncut bottom of the bottle into the open top of the other bottle. Tape or glue these two pieces together.
Straighten a coat hanger, using pliers if necessary to help you work the metal. It does not have to be perfectly straight.
Thread the straightened hanger through the holes in the bottles so that it protrudes through the blades and out the back. Spin the hanger to make the whirligig spin. For a school activity, students can take whirligigs outside to take note of wind direction and changes in speed.
Cut a vertical slit, 1/2 inch deep, into each end of a 12-inch piece of wood. Use a small saw or serrated knife to make this cut. Measure to the center point of the wood and hammer a nail straight through it, from top to bottom. Grasp the bottom of the nail and spin the wood piece around the pivot point until it spins easily.
Trace a trapezoid shape and an equilateral triangle shape into an aluminum pie plate. The shapes should each be about six inches long. Use the knife or sharp scissors to cut out the shapes.
Apply craft glue to one edge of the triangle and the short edge of the trapezoid. Insert the glued areas into the slits in the 12-inch wood stick. The trapezoid is the tail of the vane, while the triangle is the head. Allow the glue to dry before continuing.
Hold a broomstick or long wooden dowel rod vertically in front of you. Support the rod against the ground and place a small, circular washer on the end. Line up the nail in the center of your wooden stick with the center of the washer and hammer this into place, securing the vane to the dowel.
Spin the vane around to ensure that it will turn with the wind. Mount the vane on a fence, roof or other area using metal wire to record the direction of the wind.
Always supervise children working with sharp objects like scissors and nails.