Help calulating the monent of inertia

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SUMMARY

The discussion focuses on calculating the moment of inertia (MI) for a structure made of three identical thin rods, each of length L and mass M, welded perpendicularly. The user correctly identifies the formulas Icm = 1/12 ML² for a rod's moment of inertia about its center and I = 1/3 ML² for a rod's moment of inertia about an end. For Rod C, the MI is determined using I = 1/3 ML², while for Rod A, the distance of particles from the axis is considered. The Parallel Axis Theorem is applied for Rod B to find its moment of inertia.

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three identical thin rods each of length L and massM are welded perpendicluar to one another determine the monemt of inertia of the structure pink line is the axis of rotation. i think i need to use Icm= 1/12 ML^2 and I=1/3ML^2
but not sure which rod uses which formula
 

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If the pink line is passing through the end of C then the MI for Rod C is 1/3ML^2.

For MI of A, think of the distance of different particles of the rod A from the axis.

For MI of B you have to use Parallel axis theorem. Go through it.

MP
 
thanks i got it now
 

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