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From: bwood%janus.Berkeley.EDU@ucbvax.Berkeley.EDU (Blake Philip Wood)
Newsgroups: sci.military
Subject: Re: Inertia Coupling...
Keywords: inertia coupling
Message-ID: <1990Jun27.021108.1596@cbnews.att.com>
Date: 27 Jun 90 02:11:08 GMT
References: <1990Jun22.043401.28436@cbnews.att.com>
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From: bwood%janus.Berkeley.EDU@ucbvax.Berkeley.EDU (Blake Philip Wood)

In article <1990Jun22.043401.28436@cbnews.att.com> grumbly!root@uunet.UU.NET (rb duc) writes:
>->A good, simple, cheap classroom demonstration of inertia coupling is
>->to take a rubberband and put around a book.  [...]
>
>Do you know the equations?  Does aerodynamics have much effect on the process?
>How is the problem handled?

That rotation about the axis with the intermediate moment of inertia is 
unstable is a standard problem in any college mechanics class.  See
Marion, "Classical Dynamics", section 12.11 in the second edition 
(there is a 3rd edition out) on the stability of rigid-body
rotations.  Marion notes that this problem was first treated by Euler
in 1749.

                 Blake P. Wood - bwood@janus.Berkeley.EDU
                 Plasmas and Non-Linear Dynamics, U.C. Berkeley, EECS