5H20.10 - Forces on Magnets - Torque
The magnets inside the toys are arranged in such a way that when the seal is brought close to the ball, the ball will begin to spin.
When the mirror is brought close to Dancing Mary she should also begin to rotate if placed on a smooth surface.
- Raymond C. Turner, "A Physics Toy: Magnetic Seal and Ball", TPT, Vol. 25, # 9, p. 568, December 1987.
- Donna A. Berry, "A "Perpetual Motion" Toy?", TPT, Vol. 20, # 5, May 1982, p. 319.
- Jodi and Roy McCullough, "Magnetism with a Ballerina", The Role of Toys in Teaching Physics, p. 4.166.
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