Physics - Rotation Question with Solution | TestHub

Given that, moment of inertia of discs, ${\mathrm{I}}_1=2\mathrm{kg}-{\mathrm{m}}^2,{\mathrm{I}}_2=4\mathrm{kg}-{\mathrm{m}}^2$ Angular velocity of discs, ${\omega }_1=8\mathrm{rad}/\mathrm{s}$, ${\omega }_2=4\mathrm{rad}/\mathrm{s}$ From angular momentum conservation principle, ${\mathrm{I}}_1{\omega }_1+{\mathrm{I}}_2{\omega }_2=\left({\mathrm{I}}_1+{\mathrm{I}}_2\right)\omega$ or $2\times 8+4\times 4=(2+4)\omega$ or $\omega =\frac{16+16}{6}=\frac{32}{6}=\frac{16}{3}\mathrm{rad}/\mathrm{s}$