1Q60.38 - Spinning Double Spheres

Code Number:
Demo Title:
Spinning Double Spheres

Video and Editing Credit: Jonathan M. Sullivan-Wood.

Place the pair of magnetic spheres on the plate.  Give them a spin by hand and then use the compressed air can to spin them up to very high revolutions by directing the air to a tangent to the spinning spheres.  When the revolutions become high enough, you should see one end of the sphere pair raise up off the plate.

  • David P. Jackson, David Mertens, Brett J. Pearson, "Hurricane Balls: A Rigid-body-Motion Project for Undergraduates", AJP, Vol. 83, #11, Nov. 2015, p. 959.
  • David Jackson, "The Spinning Double Sphere", Physics Today, Vol. 69, #2, Feb. 2016, p. 72.

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.