1D50.45 - Central Forces - Penny & Coat Hanger

Balance the penny on the end of the hook on the hanger.  Gently, rotate the hanger until you can go full circle.  Note that the penny is held onto the end of the hook by the rotational force applied.
Code Number:
Demo Title:
Central Forces - Penny & Coat Hanger
Forces Due To Circular Motion
Area of Study:
Coat hanger bent in to a "square" form, dime.

Balance the dime on the end of the hook on the hanger.  Gently, rotate the hanger until you can go full circle.  Note that the dime is held onto the end of the hook by the rotational force and the asymmetric air stream applied. 

  • Martin Gardner, "Coat Hanger", TPT, Vol. 43, # 1, Jan. 2005, p. 4.
  • Richard A.D. Hewko,  "The Racing Car Turn",  TPT, Vol. 26, # 7, p. 436, October 1988.
  • Frank Butcher,  "Circular Motion Studies with a Toy Airplane",  TPT, Vol. 25, # 9, p. 572, December 1987.
  • Phyllis Salmons, "The Penny and the Coathanger", TPT, Vol. 15, # 1, Jan. 1977, p. 46.
  • John Dixon, "A Penny For Your Thoughts", TPT, Vol. 4, # 1, Jan. 1966, p. 38.
  • George W. Ficken, Jr., "Putting a Penny 'Into Orbit'", AJP, Vol. 40, #5, May 1972, p. 776.
  • M- 362:  "Water in Circle-Coin on Hanger",  DICK and RAE Physics Demo Notebook.


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