1D52.10 - Central Forces - Centrifugal Flattening

Code Number:
1D52.10
Demo Title:
Central Forces - Centrifugal Flattening
Condition:
Fair
Principle:
Forces Due To Circular Motion
Area of Study:
Mechanics
Equipment:
'Egg beater' (large), Toy Twirlers.
Procedure:

Spin the apparatus up to the desired speed, BUT DO NOT TRY TO STOP IT BY HOLDING ONTO THE HANDLE.  Just let go of the handle and allow it to spin down.  

CAUTION:  Keep your fingers and neckties out of the gear system.  

Hold the handles of the toy and then spin it so that the string winds up.  Pulling on the handles will make the toy spin with observable flattening.

References:
  • Martin Lieberherr, "Let's Stop Centripetal Force", TPT, Vol. 62, #1, Jan. 2024, p. 3.
  • C. H. Worner, "Let's Stop Centrifugal Force", TPT, Vol. 61, #6, Sept. 2023, p. 425.
  • Irene Tovar Hernandez, Jose Manuel Vaquero, "Flattening of Earth by Rotation: From Historical Experiment to Modern Toy", TPT, Vol. 61, #2, Feb. 2023, p. 100.
  • Spencer Perry, "The 3D-Printed Twirly Whirly: A New Spin on a Toy for Teaching Moments of Inertia", TPT, Vol. 60, #8, Nov. 2022, p. 642.
  • George Greenstein, "An Intuitive Approach to Earth's Centrifugal Bulge", TPT, Vol. 60, #5, May 2022, p. 369.
  • George Greenstein, "The Shape of Earth: An Early Test of Newtonian Physics", TPT, Vol. 60, #5, May 2022, p. 365.
  • David Heiden,  "Homemade Spinner Demonstrates Formation of Solar System",  TPT, Vol. 38, # 6, p. 378, Sept. 2000.
  • Neil M. Shea,  "Estimating the Power in the Tides",  TPT, Vol. 25, # 7, p.  426, October 1987.
  • Paul G. Hewitt, "No Agent", TPT, Vol. 19, # 1, Jan. 1981, p. 8.
  • Robert P. Bauman, "What is Centrifugal Force?", TPT, Vol. 18, # 7, Oct. 1980, p. 527.
  • J. W. Beams, " High Centrifugal Fields", TPT, Vol. 1, # 3, Sept. 1963, p. 103.
  • Jay S. Bolemon, "Addendum: 'Shape of the Rotating Planets and the Sun: A Calculation for Elementary Mechanics' [Am. J. Phys. 44, 1125 (1976)]", AJP, Vol. 46, #5, May 1978, p. 588.
  • Jay S. Bolemon, "Shape of the Rotating Planets and the Sun: A Calculation for Elementary Mechanics", AJP, Vol. 44, #11, Nov. 1976, p. 1125.
  • S- 370:  "Rotating Straps",  DICK and RAE Physics Demo Notebook. 
  • Jodi and Roy McCullough, "Inertia with a Spinner"", The Role of Toys in Teaching Physics, p. 4.72.
  • Janice VanCleave, "Global Addresses", Geography for Every Kids: Easy Activities that Make Learning Geography Fun, p. 31.
  • Borislaw Bilash II, David Maiullo, "A Shapely Planetoid", A Demo a Day: A Year of Physics Demonstrations, p. 142.
  • 1, "Bulging Ball",  Janice VanCleave,  Earth Science for Every Kid: 101 Easy Experiments That Really Work, p. 8.
  • 121, Bulging Ball, Janice VanCleave's 200 Gooey, Slippery, Slimy, Weird, and Fun Experiments.
  • Brown, "Centrifugal and Centripetal Forces", 200 Illustrated Science Exp for Children, p. 43.
  • # 127, "Flatter", Janice VanCleave's 203 Icy, Freezing, Frosty, Cool, and Wild Experiments.
  • E. Leybold's Nachfolger, "428 Two Cylinders of Unlike Material", Catalogue of Physical Apparatus
  • E. Leybold's Nachfolger, "437-439 Apparatus and Moving Balls", Catalogue of Physical Apparatus
  • "74435 Centrifugal Hoops", Scientific Instruments and Laboratory Supplies, Central Scientific Company, Catalog J-150
  • "74435 Centrifugal Hoops", Mechanics of Solids, Central Scientific Company, 1990, p. 37.
  • Joseph Frick, "#4 - Centrifugal Flattening", Physical Technics: Or, Practical Instructions for Making Experiments in Physics and the Construction of Physical Apparatus with the Most Limited Means", p. 141.
  • "Centrifugal Hoops for Showing the Earth an Oblate Spheroid", Pike's Illustrated Catalogue of Scientific & Medical Instruments, 1984, p. 117.
  • The Queen Catalogues Vol. II, Catalogue of Physical Instruments, Section IV, p. 7.


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.