For different types of bodies rotating about different axes of rotation, their moment of inertia is different. In of moment of inertia, axes theorems play an important role. Another important term used in applications of rotational motion where of inertia is used is Radius of Gyration.
of Gyration: It is the squared distance which when multiplied with the mass of a body gives the moment of inertia of a body about a given axis of rotation. It is also defined as a body which has the same mass as that of a rotating body when it moves in a circle. If its moment of inertia is the same as that of a rotating body about the given axis of rotation, then the radius of circle is termed as radius of gyration of the rotating body about the specific axis of rotation.
See the video below to understand the Radius of Gyration –
In previous we discussed that axes theorems are used for calculation of moment of inertia in different cases. To understand the applications of axes theorems in different cases of moment of inertia see the example videos below –