Question

Four identical masses of 2 kg each are situated at the four corner of the square. A side of the square measures 3.0m. Find the moment of inertia about an axis passing through the center of the square and perpendicular to its plane

Answer 1

Explanations & Calculations

• It is the sum of M.O.Is of each mass around the axis.

$\qquad\qquad \begin{aligned} \small I&=\small \Sigma mr^2\\ &=\small (\sqrt{\frac{3\sqrt2}{2}\,m})^2\Big[2\,kg+2\,kg+2\,kg+2\,kg\Big]\\ &=\small 36\,kgm^2 \end{aligned}$