Radius of gyration

Radius of gyration:

Theoretical calculation of moment of inertia is possible only for mathematically integrable geometrical shapes. However, experimentally we can determine the MI of any object. It depends upon mass of that object and how that mass is distributed from or around the given axis of rotation. If we are interested in knowing only the mass distribution around the axis of rotation, we can express moment of inertia of any object as I = MK2 , where M is mass of that object. It means that the mass of that object is effectively at a distance K from the given axis of rotation. In this case, K is defined as the radius of gyration of the object about the given axis of rotation. In other words, if K is radius of gyration for an object, I = MK2 is the moment of inertia of that object. Larger the value of K, farther is the mass from the axis.