
For a solid dm = r dV where r is the density function and dV is a differentially small volume.

There is a simple relationship between the moment of inertia about the center of mass of a body Icm and the moment of inertia about some other point that is a distance d from the center of mass provided both axes of rotation are parallel.
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* If you know the moment of inertia about the center of mass you, can find it about ANY pivot point by using the parallel axis theorem, provided the axis of rotation is parallel.
Moment of Inertia of Simple Solids:
Solid Sphere

Spherical Shell

Hoop or
Cylindrical Shell

Solid Cylinder
or Thin Disk

Thin Rod or Bar

Thin Rod about its end

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