Physics - Rotation Question with Solution | TestHub

Mass $(m)=2\mathrm{kg}$; initial radius of the path $\left(r_1\right)=0.8\mathrm{m}$; initial angular velocity $\left({\omega }_1\right)=44\mathrm{rad}/\sec$ and final radius of the path $\left(r_2\right)=1\mathrm{m}$ Moment of inertia, $I_1=m{r}_1^2=2\times (0.8{)}^2$ $=1.28\mathrm{kg}{\mathrm{m}}^2$ and $I_2=m{r}_2^2=2\times (1{)}^2=2\mathrm{kg}{\text{m }}^2$ Therefore from the law of conservation of angular momentum $I_1{\omega }_1=I_2{\omega }_2$ or ${\omega }_2=\frac{I_1\times {\omega }_1}{I_2}=\frac{1.28\times 44}{2}$ ${\omega }_2=28.16\mathrm{rad}/\sec$