Physics - Rotation Question with Solution | TestHub

We should use parallel axis theorem. Moment of inertia of disc passing through its centre of gravity and perpendicular to its plane is$I_{AB}=\frac{1}{2}M{R}^2$ Using theorem of parallel axes, we have $\begin{array}{rl}{I}_{CD}& =I_{AB}+M{R}^2\\ & =\frac{1}{2}M{R}^2+M{R}^2\\ & =\frac{3}{2}M{R}^2\end{array}$ NOTE : The role of moment of inertia in the study of rotational motion is analogous to that of mass in study of linear motion.