TRANSLATION AND ROTATION 15
12. Values of the Moment of Inertia of Certain Bodies. - The moments of inertia of a body, having regular geometrical shape, can be computed, but the moments of inertia of a body of irregular shape are usually most easily determined by experiment. The experimental determination is usually made by comparison with a body of known moment of inertia. For such comparisons cylinders and rings of known dimensions are convenient.
It is shown in books on Mechanics that the moment of inertia of a uniform right solid cylinder of mass m and diameter d, about its geometric axis, is
s md2 (22
whereas about any axis parallel to the geometric axis and dicta p from it, the moment of inertia is
8 md2 + mpg (23)
If the cylinder has a length x, the moment of inertia about an axis through the center and normal to the length is
16 12) (24)