Two identical rods of mass M and length l are lying in a horizontal plane at an angle α. The moment of inertia of the system of two rods about an axis passing through O and perpendicular to the plane of the rods is

Question

Two identical rods of mass M and length l are lying in a horizontal plane at an angle α. The moment of inertia of the system of two rods about an axis passing through O and perpendicular to the plane of the rods is (A) M l2 / 3 (B) M l2 / 12 (C) M l2 / 4 (D) M l2 / 6

Tardigrade Admin · Accepted Answer

The angle between the rods will not make any difference. ∴ Net moment of inertia, I=I1+I2 =(M l2/12)+(M l2/12)=(M l2/6)

Q. Two identical rods of mass $M$ and length $l$ are lying in a horizontal plane at an angle $α$ . The moment of inertia of the system of two rods about an axis passing through $O$ and perpendicular to the plane of the rods is

$M l^{2} /3$

$M l^{2} /12$

$M l^{2} /4$

$M l^{2} /6$

The angle between the rods will not make any difference.
$∴$ Net moment of inertia,
$I = I_{1} + I_{2}$
$= \frac{M l ^{2}}{12} + \frac{M l ^{2}}{12} = \frac{M l ^{2}}{6}$

Q. Two identical rods of mass M and length l are lying in a horizontal plane at an angle α. The moment of inertia of the system of two rods about an axis passing through O and perpendicular to the plane of the rods is

Ml2/3

Ml2/12

Ml2/4

Ml2/6