Question

​the moment of inertia of a circular disc about an axis passing through its center and perpendicular to its plane is MR sq +2 . find its moment of inertia about an axis passing through its edge and parallel to its diameter ​

Answer 1

Dear student

$$\begin{gathered} I_{zcentre}=\frac{m{r}^2}{2} \\ {I}_x+I_y=I_z \\ {I}_y=I_{x}duetosymmetry \\ 2I_x=I_z \\ {I}_x=\frac{m{r}^2}{4} \\ {I}_{required}=I_X+m{r}^2 \\ {I}_{required}=\frac{m{r}^2}{4}+m{r}^2=\frac{5m{r}^2}{4} \end{gathered}$$

Make use of parallel and perpendicular axis theorm

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