Moment of inertia of an ellipse formula

AI Thread Summary
The formula for the moment of inertia of an ellipse about its centroidal axis is M*(a^2 + b^2)/4, which is confirmed as correct. The alternative formula found on a webpage, Pi*a*(b^3)/4, refers to the area moment of inertia, not the mass moment of inertia. It's important to distinguish between these two concepts to avoid confusion. Understanding the definitions of area moment and mass moment of inertia is crucial for accurate calculations. The initial formula provided is indeed valid for the mass moment of inertia.
Vineeth T
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hello!
I have to verify the formula of the moment of inertia of an ellipse about its' centroidal axis,
is it M*(a^2 + b^2)/4.This is the one I got by myself.
But in a webpage it was given as Pi*a*(b^3)/4.

NOTE: don't ask for the proof of what I did.Its' a bit longer.I just want to know whether its' correct or
not.
 
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You are mixing things up. The Quantity given on the webpage is is the "Area moment of Intertia" not the mass moment of inertia. Read on the two quantities and then you will see what to do...
 
Ok then what I found out was correct.
 

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