Science Buddies: Spinning Your Wheels: Pinwheel Sensitivity

So you've just heard the "Happy Birthday" song and now it's time to blow out the candles. If you are sitting far away from the candles, you know you'll have to blow harder to get them all out than if you were sitting closer. In this science fair project, you'll blow on different kinds of pinwheels with a blow-dryer and see how far away you can get before they stop spinning. This will give you clues about how sensitive the pinwheels are to wind, and why.