Physics - Rotation Question with Solution | TestHub

From the theorem of parallel axis, the moment of inertia $I$ is equal to $I=I_{\mathrm{CM}}+M{a}^2$ where $I_{\mathrm{CM}}$ is moment of inertia about centre of mass and $a$ the distance of axis from centre. $\therefore I=M{K}^2+M\times (6{)}^2$ $M{K}_1^2=M{K}^2+36M$ $\Rightarrow K_1^2=K^2+36$ $\Rightarrow (10{)}^2=K^2+36$ $\Rightarrow K^2=100-36=64$ $\Rightarrow K=8\mathrm{cm}$