1F20.34 - Inertia of Rest - Coin/Card Snap - Daruma Otoshi

Code Number:
Demo Title:
Inertia of Rest - Coin/Card Snap - Daruma Otoshi
Inertia of Mass
Area of Study:
Inertia App., Note cards, Tissue Paper, Pennies, Tongue Depressor.

Set the demo up with a note card between the ball or marble and the cup. Hit the note card with the spring striker and the card will fly out from underneath the ball and the ball will fall straight down into the cup. (For more dramatic effect the instructor may try to pull a tablecloth from underneath some table settings. (PIRA Demonstration Bibliography 1F20.30).

Make a stack of pennies.  Swing the tongue depressor against the bottom penny and the penny should shoot out leaving the stack intact.

  • Michael Vollmer, Klaus-Peter Mollmann, "Removing Coins from a Dice Tower: No Magic - Just Physics", TPT, Vol. 51, #4, Apr. 2013, p. 212. 
  • Mike Shaw, "I "Saw" Newton's Three Laws", TPT, Vol. 50, #8, Nov. 2012, p. 480.
  • Martin Gardner, "Bottle, Hoop, and Dime", TPT, Vol. 32, #2, Feb. 1994, p. 80.
  • T.P. Toepker,  "Newton and the Apples",  TPT, Vol. 26, #3, p. 165, March 1988.
  • Alfred M. Eich, "Inertia Demonstration",  TPT, reprints Apr. 1963-Dec. 1971, p. 162.
  • Mario Iona, "Inertia", TPT, Vol. 7, #8, Nov. 1969, p. 457.
  • Alfred Eich, "The Author Replies", TPT, Vol. 7, #8, Nov. 1969, p. 457.
  • Alfred M.Eich, "Inertia Demonstration", TPT, Vol. 6, #9, Dec. 1968, p. 477.
  • Thomas B. Greenslade, Jr., "Inertia Demonstration (photo)", AJP, Vol. 76, # 1, Jan. 2008, p. 72.
  • M- 234:  "Egg & Pie Pan-Nickels & Ruler", DICK and RAE Physics Demo Notebook.
  • M- 230: "Pen and Embroidery Hoop", DICK and RAE Physics Demo Notebook.
  • M- 226:  "Coin-Card-Glass & Ball-Card", DICK and RAE Physics Demo Notebook.
  • Charles Vivian, "The Inert Coins", Science Experiments & Amusements For Children, p. 90.
  • Martin Gardner, "A Snap and a Drop", Science Tricks, p. 29.
  • Martin Gardner, "Snap the Checker", Entertaining Science Experiments with Everyday Objects, p. 125.
  • Vicki Cobb and Kathy Darling, "Stacked Odds", Bet You Can!, p. 82.
  • Janice VanCleave, "79, Snap!", Teaching the Fun of Physics, p. 120.
  • Janice VanCleave, "81, Penny Snap", Teaching the Fun of Physics, p. 122.
  • Robert Ehrlich, "Shooting a Penny Out From Under a Stack of Pennies", Turning the World Inside Out, p. 21.
  • Walpole, "The Lazy Coin", 175 Science Experiments, p. 102.
  • Walpole, "Demolish the Tower", 175 Science Experiments, p. 103.
  • Tik L. Liem, "Pull The Dollar Bill Out?", Invitations to Science Inquiry - Supplement to 1st and 2nd Ed. p. 132.
  • Borislaw Bilash II, “The Magic Mallet“, A Demo A Day – A Year of Physical Science Demonstrations, p. 228.
  • "Inertia Apparatus", Pike's Illustrated Catalogue of Scientific & Medical Instruments, 1984, p. 141.

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.