Question

Three point masses, each of mass m, are situated at the three corners of an equilateral triangle of each side l. The moment of inertia of this system about one of the sides of the triangle will be –

• A. ml²
• B. 3ml²
• C. $\frac { 3 } { 4 }$ ml²
• D. $\frac { 2 } { 3 }$ ml²

Answer 1

Answer: (C)

$\frac { 3 } { 4 }$ ml²

Answer 2

I = (0) + (0) + m $\left( \frac { \sqrt { 3 } } { 2 } \ell \right) ^ { 2 }$

= $\frac { 3 } { 4 }$ ml²