A ring, a solid sphere and a disc have same mass and radius. Which of them have the largest moment of inertia?
A ring, a solid sphere and a disc have same mass and radius. Which of them have the largest moment of inertia?
All have the same moment of inertia
Solid sphere only
Ring only
Disc only
Solution
Formula for moment of inertia are listed below:
$I_{\text {Ring }}=M R^2$
$I_{\text {Sphere }}=\frac{2}{5} M R^2$
$I_{\text {Disc }}=\frac{1}{2} M R^2$
Ring has largest moment of inertia as the mass is distributed far away from the axis of rotation. Above formulas just confirm that.