How can I find the inertia of a rod with a pivot point?

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To find the inertia of a rod with a pivot point, the formula involves the parallel axis theorem, which states I = Ic + md², where Ic is the moment of inertia about the center of mass (CM) and d is the distance from the CM to the pivot. The moment of inertia for a rod about its CM is given by Ic = mL²/12. When the pivot is located at 2L/3 from one end, the distance d is calculated as L/6. Therefore, the total moment of inertia can be expressed as I = mL²/12 + m(2L/3)², confirming the use of the parallel axis theorem for this scenario. Understanding these principles is essential for accurately calculating the inertia of the rod.
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I have a question on finding the inertia of a rod with a pivot point somewhere along it's length.

So the inertia of a rod is IStick cm = 1/12 *m*L2
Does L2 = (2L/3)2 = 4L2/9 -> 1/12 *m*[4L2/9] or is it something like
m*L2/12 + m* (2L/3)2?

If it's the second one then may I ask why it's that?

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Revise parallel axis theorem; I = Ic + (md^2) Ic is MI about CM and d is the distance between parallel axes passing through CM and pivot. It can be proved first and then can be used.
 
Let'sthink said:
Revise parallel axis theorem; I = Ic + (md^2) Ic is MI about CM and d is the distance between parallel axes passing through CM and pivot. It can be proved first and then can be used.

so m*L2/12 + m* (2L/3)2
where Ic = m*L2/12
and md^2 = m* (2L/3)2when you said "MI about CM" you mean the mass around the center mass which is the entire rod? As for d is the "distance between parallel axes passing through CM and pivot" meaning the length between the end of the stick pass the center mass where it ends at the pivot?
 
center of mass is at the mid point of rod at L/2 from one end and if pivot is at 2L/3 from one end then d = (2L/3) - (L/2) = L/6. Ic is the MI about the axis passing through the point at L/2 from one end.
 

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