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Homework Help: Moment of inertia of a thin spherical shell

  1. Feb 8, 2008 #1
    Can anyone help me how to calculate the moment of inertia of a thin spherical shell? Thank you
  2. jcsd
  3. Feb 8, 2008 #2


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    Welcome to PF,

    One is expected to show some effort in solving before asking for help. However, I will offer you a hint: A spherical shell can be built up by summing up the moments of inertia for an infinite number of infinitesimally small hoops.
  4. Feb 8, 2008 #3
    The parallel axis theorem helps in calculating moments of inertia of homogeneous rigid bodies with strange geometries. The general equation is:

    I (moment of inertia) = Icm + MD^2

    In the case of a thin spherical shell it is:


    The "cm" is in subscript by the way. Icm is the moment of inertia about an axis through the center of mass. R is the distance from the center of mass. Hope this helps!
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