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JEE Main 202124 FebruaryEvening Shift
Exam
JEE Main
Year
2021
Date
24 February
Shift
Evening Shift
Subject
Physics
Chapter
Rotational Motion

JEE Main 2021 · 24 February · Evening Shift · Physics · Rotational Motion

A uniform thin bar of mass 6kg and length 2 . 4 meter is bent to...

A uniform thin bar of mass 6kg6kg and length 2.42 . 4 meter is bent to make an equilateral hexagon. The moment of inertia about an axis passing through the centre of mass and perpendicular to the plane of hexagon is ___________ ×10−1kgm2.\times {10}^{- 1}kg{m}^{2} .A uniform thin bar of mass 6kg and length 2 . 4 meter is bent to make an equilateral hexagon. The moment of inertia

Correct answer

0

Step-by-step solution

A uniform thin bar of mass 6kg and length 2 . 4 meter is bent to make an equilateral hexagon. The moment of inertia

61=2.461 = 2 . 4 ℓ=0.4mℓ = 0 . 4m

sin⁡60°=rℓ\sin 60 ° = \dfrac{r}{ℓ}

r=1sin⁡60°=ℓ32r = 1\sin 60 ° = \dfrac{ℓ\sqrt{3}}{2}

MOI, I=[mℓ212+mr2]6I = \left[\dfrac{m{ℓ}^{2}}{12} + m{r}^{2}\right]6

=[mℓ212+m(ℓ32)2]6= \left[\dfrac{m{ℓ}^{2}}{12} + m{\left(\dfrac{ℓ\sqrt{3}}{2}\right)}^{2}\right]6

=5ml2= 5m{l}^{2}

=5×1×0.16= 5 \times 1 \times 0 . 16

=0.8= 0 . 8

I=8×10−1kgm2I = 8 \times {10}^{- 1}kg{m}^{2}

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