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Moment of Inertia of Disk at any point

  1. Aug 15, 2007 #1
    As we know the moment of Inertia of a disc in the center of mass equals 0.5mr^2

    My Simple question is: what is the moment of inertia of the disc at any other point? as I know there is a formula that supports the distance from the center of mass,

    and is there a relation for 3D shapes?

    Thanks
     
  2. jcsd
  3. Aug 16, 2007 #2
    Do you know the parallel axis theorem?

    The moment of inertia for an object rotating about an axis that does not pass through its centre of mass, but which is parallel to it, is

    mr^2 + (moment of inertia about an axis through the centre of mass and parallel to the other axis)

    The r is the distance from the axis to the centre of mass.
     
  4. Aug 16, 2007 #3
    Thank you, I know that law but this was 3 years ago, Thank you for reminding me, This post is closed!!
     
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