2B40.15 - Buoyancy - Finger, Water, and Scale

Code Number:
2B40.15
Demo Title:
Buoyancy - Finger, Water, and Scale
Condition:
Excellent
Principle:
Buoyancy
Area of Study:
Heat & Fluids
Equipment:
Digital Scale, Beaker, and Water.
Procedure:

Place the beaker of water on the scale and tare the scale.  As you press your finger into the water the scale reading will increase.  Basically this reading is a direct measurement of the buoyant force that the water is exerting on the finger.

References:
  • Amanda C. Tenhoff, Adam J. Gerenz, and Jeffrey A. Jalkio, "Buoys and Springs – Building Connections Between Math and Physics", TPT, Vol.54, #9, Dec. 2016, p. 556.
  • Alpha E. Wilson, "Buoyant Beaker Balls: Another View", TPT, Vol. 54, #8, Nov. 2016, p. 452.
  • Paul Hewitt, "Hewitt's Response", TPT, Vol. 54, #3, Mar. 2016, p. 132.
  • Carl Mungan, "Buoyant Beaker Balls", TPT, Vol. 54, #3, Mar. 2016, p. 132.
  • Paul Hewitt, "Answer to January 2016 Figuring Physics Question", TPT, Vol. 54, #2, Feb. 2016, p. 124.
  • Pirooz Mohazzabi and Mark C. James, "A Simple Apparatus for Demonstrating Fluid Forces and Newton's Third Law", TPT, Vol. 50, #9, Dec. 2012, p. 537.
  • James J. Carr, "Demonstrating Newton's Third Law", TPT, Vol. 42, #3, Mar. 2004, p. 132.
  • Paul Hewitt, "Figuring Physics: Submerged Teabag", TPT, Vol. 41, #7, Oct. 2003, p. 384.
  • Paul Hewitt, "Figuring Physics: Beaker and Water", TPT, Vol. 39, #4, Apr. 2001, p. 204.
  • Eric Kincanon, "Explanation of a Buoyancy Demonstration", TPT, Vol. 33, #1, Jan. 1995, p. 31.
  • Robert Ehrlich, "6.3, Buoyant Force on your Finger", Why Toast Lands Jelly-Side Down, p. 102.
  • R. W. Pohl, "7. The Upward Thrust of Liquids on Solid Bodies Immersed in Them", Physical Principles of Mechanics and Acoustics, p. 163.
  • Martin Gardner, "Finger in the Bowl", Entertaining Science Experiments with Everyday Objects, p. 83.
  • Borislaw Bilash II and David Maiullo, "Fingering Out Buoyancy", A Demo a Day: A Year of Physics Demonstrations, p. 188.
  • Janice VanCleave, "4, Weigh Your Hand", Teaching the Fun of Physics, p. 13.


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.