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  1. J

    Centre of Mass Theorem false for a rotating body?

    Let's consider things simply. The forces acting on the centre of mass are gravity, and the reaction of the table to the support. So another torque must come from the fact that it is precessing, or maybe from spinning? or a combination of the two? I never knew that a gyroscope could generate an...
  2. J

    Centre of Mass Theorem false for a rotating body?

    But surely the centre of mass traces out a circle as it precesses, the com being in the centre of the fly wheel?
  3. J

    Centre of Mass Theorem false for a rotating body?

    For a distributed mass, F = M dv/dt where F is the total external force, M the total mass, and v the velocity of the centre of mass. But take the case of a gyroscope, where the force acting on the centre of mass is gravity, assuming it is uniform over the body. The gyroscope doesn't topple...
  4. J

    Some questions on rigid modies in Landau's Mechanics book

    The following comes from Landau's Mechanics, pages 97 - 98. For a particle in a rigid body, v = V + W x r -- (1) where for some origin O of the moving body measured in the "fixed" system of co-ordinates, v = particle's velocity in the "fixed" system, V = velocity of O in "fixed" system...
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