1J20.30 - Sky Hook
This system will appear to balance on the edge of a table or a finger. The reason is because the brass weight must move upward in any direction for the system to fall off a table or a finger tip.
- Terrence P. Toepker, "More Belt Hook Mechanics", TPT, Vol. 42, # 2, Feb. 2004, p. 70.
- Terrence P. Toepker, "A Center of Gravity Demonstration", TPT, Vol. 15, # 4. Apr. 1977, p. 241, reprinted in TPT, Vol. 41, # 9, Dec. 2003, pg. 549.
- Ray Turner, "100 Years of Physics and Toys: Balancing Toys", TPT, Vol. 30, # 9, p. 542, Dec. 1992.
- Scott Welty and Norbert Zarumba, "The Pendulum and the Apple", TPT, Vol. 21, # 6, Sept. 1983, p. 340.
- James Watson, Jr., Nancy T. Watson, "Pocketbook Science", TPT, Vol. 20, # 4, Apr. 1982, p. 235.
- Vincent Buckwash, "Ways to Demonstrate Center of Gravity", TPT, Vol. 14, # 1, January 1976, p. 39.
- Terrence P. Toepker, " More Center of Gravity", TPT, Vol. 14, # 8, , Nov. 1976, p. 499.
- Mp- 3, 4: Freier and Anderson, A Demonstration Handbook for Physics.
- M- 470: "Hammer on Hinged Board & Loop", DICK and RAE Physics Demo Notebook.
- M- 33: Richard Manliffe Sutton, Demonstration Experiments in Physics.
- Vincent Buckwash, "Ways to Demonstrate Center of Gravity", A Potpourri of Physics Teaching Ideas, Jan 1976, p. 39.
- Carson I. A. Ritchie, "The Balancing Horse", Making Scientific Toys, p. 92.
- "Decorative Toys and Boxes Made at Home", The Boy Mechanic Makes Toys, p. 199.
- Cy Tymoney, "Sneaky Balancer III", Sneakiest Uses for Everyday Things, p. 15 .
- Brown, "A Gravity Trick", 333 More Science Tricks and Experiments, p. 48- 49.
- Janice VanCleave, "Over the Edge", 200 Gooey, Slippery, Slimy, Weird & Funny Experiments, p. 95.
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