The moment of inertia of a solid sphere of mass 20 kg and diameter 20 cm about the tangent to the sphere is
The moment of inertia of a solid sphere of mass 20 kg and diameter 20 cm about the tangent to the sphere is
$0.24 \mathrm{kgm}^2$
$0.14 \mathrm{kgm}^2$
$0.28 \mathrm{kgm}^2$
$0.08 \mathrm{kgm}^2$
Solution
$\mathrm{m}=20 \mathrm{~kg}, \mathrm{~d}=20 \mathrm{~cm} \therefore \mathrm{r}=10 \mathrm{~cm}$
$\therefore$ The moment of inertia of a solid sphere about its tangent is
$\mathrm{I}=\frac{2}{5} \mathrm{mr}^2+\mathrm{mr}^2=\frac{7}{5} \mathrm{mr}^2=\frac{7}{5} \times 20 \times 10 \times 10 \times 10^{-4}$
$=0.28 \mathrm{~kg} \mathrm{~m}^2$