PURPOSE: To illustrate the effect rotation about the various principal axes on stability.
DESCRIPTION: The book is held together tightly using several rubber bands. Throw the book in the air, spinning it about the axes with either its minimum or its maximum moment of inertia; the book spins in a constant orientation and returns to your hands normally. Throw the book in the air, spinning about the axis with its intermediate moment of inertia. The book flips before it returns to your hands, indicating that rotation about this intermediate axis is unstable.
REFERENCES: (PIRA 1Q60.40) See Demonstration Reference File for further information, including derivation of the equations which help to explain this weird phenomenon.
EQUIPMENT: Book with rubber bands.
SETUP TIME: None.
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