Three identical rods each of mass M , length l are joined to form an equilateral Δ ABC . Find the Moment of Inertia about BC as shown.

Question

Three identical rods each of mass M , length l are joined to form an equilateral Δ ABC . Find the Moment of Inertia about BC as shown. <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/p-elnfqtekqdsy.png" /> (A) (2/3)Ml2 (B) (M l2/4) (C) (M l2/2) (D) none

Tardigrade Admin · Accepted Answer

I=I1+I2+I3=(M(l sin 60°)2/3)+(M(l sin 60°)2/3)+0=(M l2/2)

Q. Three identical rods each of mass $M$ , length $l$ are joined to form an equilateral $Δ A BC$ . Find the Moment of Inertia about $BC$ as shown.

$\frac{2}{3} M l^{2}$

$\frac{M l ^{2}}{4}$

$\frac{M l ^{2}}{2}$

none

$I = I_{1} + I_{2} + I_{3} = \frac{M ( l s i n 6 0 ^{\circ} ) ^{2}}{3} + \frac{M ( l s i n 6 0 ^{\circ} ) ^{2}}{3} + 0 = \frac{M l ^{2}}{2}$

Q. Three identical rods each of mass M , length l are joined to form an equilateral ΔABC . Find the Moment of Inertia about BC as shown.

32​Ml2

4Ml2​

2Ml2​