Question

The ABC is a triangular plate of uniform thickness. The sides are in the ratio shown in the figure. I$_{AB}$, I$_{BC}$ and I$_{CA}$ are the moments of inertia of the plate about AB, BC and CA respectively. Which one of the following relations one is correct ?

• A. $I_{AB}+I_{BC}=I_{CA}$
• B. $I_{CA}$ is maximum
• C. $I_{AB} > I_{BC}$
• D. $I_{BC} > I_{AB}$

Answer 1

Answer: (D)

$I_{BC} > I_{AB}$

Answer 2

The intersection of medians is the centre of mass of the triangle. Since the distances of centre of mass from the sides is related as x$_{BC} < x_{AB} < x _{AC}$.
Therefore I$_{BC}$ > I$_{AB}$ > I$_{AC}$ or I$_{BC}$ > I$_{AB}$ .