Two black wooden plates (odd-shaped), and blunted screwdriver mass hanger

Code Number: 1J10.12

Demo Title: Wooden Plates

Condition: Good

Principle: Center of Mass

Area of Study: Mechanics

Equipment: 

Wooden plates (2, black) (odd-shaped), and Blunted Screwdriver Mass Hanger.

Procedure: 

Place the wooden plate on the screwdriver hanger. Hang the plumb bob from the hanger also. Draw straight lines down the plumb bob, then hang the wooden plate from one of the different holes and draw another line. After this is done two or three times the lines should intersect at a point. This should be the center of mass of the object.

References:

  • Francisco Jose Torcal-Milla, "Video-Aided Observation of the Center of Mass of Plane Objects", TPT, Vol. 62, #1, Jan. 2024, p. 12.
  • Charles J. Reidl, Jr., "Three Methods of Finding Center of Mass", TPT, Vol. 33, # 2, p. 126-127, Feb. 1995.
  • James Casey, "Exploring Properties of Forces in Equilibrium", TPT, Vol. 32, # 6, Sept. 1994, p. 364.
  • Thomas B. Greenslade, Jr.,  "Center of Mass Demonstrations Using Ceiling Tile",  TPT, Vol.  30, # 4, p. 240, April 1992.
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  • R. D. Edge, "Center of Mass", TPT, Vol. 22, # 8, Nov. 1984, p. 535 - 537.
  • Adel Alameh, "Static Equilibrium in a Uniform Gravitational Field", TPT, Vol. 61, #4, Apr. 2023, p. 298.
  • Jose M. Campillo-Robles, Ibon Alonso, Ane Gondra, Nerea Gondra, "Calculation and Measurement of Center of Mass: An All-In-One Activity Using Tangram Puzzles", AJP, Vol. 90, #9, Sept. 2022, p. 652.
  • Albert A. Bartlett, Richard L. Conlkin,  "U.S. Population Dynamics",  AJP, 53, # 3, March 1985.
  • M- 466:  "Virginia & Other Irreg. Shapes",  DICK and RAE Physics Demo Notebook.
  • M- 32:  Richard Manliffe Sutton, Demonstration Experiments in Physics.
  • R. W. Pohl, "The Rotation of Rigid Bodies", Physical Principles of Mechanics and Acoustics, p. 97.
  • Guenter Schwarz, "Center of Mass", Apparatus Notes, July 1965-December 1972, p. 56.
  • Charles Vivian, "Finding the Center of Gravity", Science Experiments & Amusements For Children, p. 12.
  • David Kutliroff, "47, Center of Mass Demonstrations with a Plywood 'Amoeba'", 101 Classroom Demonstrations and Experiments For Physics Teachers, p. 105.
  • Martin Gardner, "Balancing Point", Entertaining Science Experiments with Everyday Objects, p. 85.
  • Borislaw Bilash II, David Maiullo, "Where's the Middle?", A Demo a Day: A Year of Physics Demonstrations, p. 148.
  • Janice VanCleave, "70, Balancing Blob", Teaching the Fun of Physics, p. 109.
  • Janice VanCleave,  "Downward",  Physics for Every Kid - 101 Easy Experiments in Motion, Heat, Light, Machines, and Sound,  p. 88- 89.
  • "Center of Mass of Odd Shaped Objects", Physics From the Junk Drawer, 3rd Edition, The Science House, North Carolina State University, p. 21.
  • Julius Sumner Miller,  "Cenco-Miller Center of Mass Demonstration",  Physics fun and Demonstrations. p.141.
  • Tik L. Liem, "Where Is The Balancing Point?", Invitations to Science Inquiry - Supplement to 1st and 2nd Ed. p. 99.
  • Borislaw Bilash II, “Where's the Middle?“, A Demo A Day – A Year of Physical Science Demonstrations, p. 208.
University of Maryland Physics Department QOTW Question #96
University of Maryland Physics Department QOTW Answer #96