1G20.50 - Magnet & Keeper

Code Number:
Demo Title:
Magnet & Keeper
Free Fall
Area of Study:
Magnet glued to Plexiglass holder, keeper, foam pad.

Show that the keeper will be attracted to the magnet if brought close enough.  Then, lay the keeper on the bottom ledge of the Plexiglass.  Hold about two feet above the foam pad and drop.  You can hear the keeper click against the magnet when the gravitational pull no longer acts on the keeper during free-fall. 

  • Heladio Ayala, Josip Slisko, Adrian Corona, "Magnetic Demonstration of Weightlessness: A Spark of Student Creativity", TPT, Vol. 49, # 8, Nov. 2011, p. 524.
  • John D. McGervey, "Hands-on Physics for Less Than a Dollar per Hand", TPT, Vol. 33, # 4, Apr. 1995, p. 238 - 241.

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.