Perpendicular axis theorem ( at moments of inertia)


Perpendicular axis theorem (or plane figure theorem) can be used to determine the moment of inertia of a rigid object that lies entirely within a plane, about an axis perpendicular to the plane, given the moments of inertia of the object about two perpendicular axes lying within the plane. The axes must all pass through a single point in the plane.
If a body lies in the xy plane and the z axis is perpendicular to the plane of the body, then the moment of inertia about the z axis is the sum of the moments of inertia at the x and y axes.

Related formulas


IzMoment of inertia (Perpendicular axis ) (kg*m2)
IxMoment of inertia ( axis x) (kg*m2)
IyMoment of inertia ( axis y) (kg*m2)