Physics - Rotation Question with Solution | TestHub

The radius of gyration ($k$) of a body about an axis is defined such that if the entire mass ($M$) of the body were concentrated at a distance $k$ from the axis, its moment of inertia would be the same as that of the actual body.

Therefore, the relationship between moment of inertia ($I$), mass ($M$), and radius of gyration ($k$) is given by the formula $$I=M{k}^2$$.