Education aerodynamics "Finger Spinner"

What Makes a Helicopter Fly? In order to fly, an object must have lift—that is, a force moving it upward. Lift is usually made by wings. Wings create lift because of a relationship called the Bernoulli Principle. The Bernoulli Principle describes how the speed of air and the pressure in the air are related. When the speed goes up, the pressure goes down. The opposite is also true. Wings are curved on top and flatter on the bottom. This shape is called an airfoil. That shape makes air flow over the top faster than under the bottom. As a result, there is less air pressure on top of the wing. This makes the wing move up. A helicopter's rotor blades are spinning wings that create lift. An airplane must fly fast to move enough air over its wings to provide lift. A helicopter moves air over its rotor by spinning its blades. The rotor makes the lift that carries the helicopter up.   Source: http://www.nasa.gov/audience/forstudents/5-8/features/what-is-a-helicopter-58.html   Flying your Finger Spinner! Hold the Finger Spinner with the propeller up and the shaft in your right hand, between your middle finger and thumb. Grip it firmly and then make a quick snapping motion—much like snapping your fingers. Your Finger Spinner should spin counterclockwise. NOTE: If you are left handed, follow the instructions above, but hold your Finger Spinner upside down when you snap!   Finger spinner from Reg Taylor on Vimeo.