Question

A thin rod has mass \(100\,g\) and length \(0.3\,m\). Find its moment of inertia about an axis passing through its centre of mass and perpendicular to its length.

• A. \(2.5\times10^{-4}\,kg\,m^2\)
• B. \(5.0\times10^{-4}\,kg\,m^2\)
• C. \(7.5\times10^{-4}\,kg\,m^2\)
• D. \(1.0\times10^{-3}\,kg\,m^2\)

Hint:

For a uniform rod: \[ I_{centre}=\frac{1}{12}ML^2, \qquad I_{end}=\frac{1}{3}ML^2. \] Always identify the axis carefully before choosing the formula.

Answer 1

The Correct Option is C