An annular ring has mass 10 kg and inner and outer radii are 10 m and 5 m respectively. Its moment of…
An annular ring has mass 10 kg and inner and outer radii are 10 m and 5 m respectively. Its moment of inertia about an axis passing through its centre and perpendicular to its plane is
$525 \mathrm{kgm}^2$
$625 \mathrm{kgm}^2$
$525 \mathrm{gcm}^2$
$625 \mathrm{gcm}^2$
Solution
Quantity for Mass
The moment of inertia of the annular ring is
$\begin{aligned}
I & =\frac{1}{2} M\left(R_1^2+R_2^2\right) \\
& =\frac{10(100+25)}{2}=625 \mathrm{kgm}^2
\end{aligned}$