Electric Whirl
Category : physics
Product Detail
The Electric Whirl, also commonly known as the Electric Pinwheel or Electric Mill, is a simple, captivating demonstration device used in electrostatics to illustrate the principle of electrostatic repulsion and the concept of electric wind created by sharp points. It consists of several pointed wires radiating from a central pivot point, balanced so that the assembly can rotate freely. When the central pivot is connected to a high-voltage electrostatic generator, such as a Van de Graaff or Wimshurst machine, the sharp points accumulate a high density of charge. This intense concentration of charge causes the surrounding air molecules to become ionized with the same polarity and immediately repelled from the points. The cumulative reaction force from the continuous stream of repelled ionized air (the "electric wind" or corona discharge) exerts a small thrust on the pinwheel at each point, causing the entire assembly to rotate rapidly in the opposite direction, clearly demonstrating the momentum transfer generated by the expulsion of charge.
