Hey ppl it's my first post wohooo. :)(adsbygoogle = window.adsbygoogle || []).push({});

I've been trying o solve this problem for ages and seriously i don't know what i'm doing wrong... It's not a difficult problem but i can't seem to solve it.

I have to calculate the MoI of this figure:

http://mypicfordc.com.sapo.pt/moi.JPG

Where a=89.9 [cm], b=57.8 [cm], c=44.8 [cm]

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I've been able to accuraely calculate the centroid of the figure (xG=50.261 ; yG= 44.607) and i've reached a MoI value that is close to the solution but it's not close enough to be considered correct.

My MoI values are:

Ix= 5305338 ; Iy= 4131811 ; Ixy= 1580647

Correct values are surrounding:

Ix= 5800000 ; Iy= 4700000 ; Ixy= 1500000 (not completely accurate, just an aprox.)

The main values are all correct (Areas, xGi, yGi, Sxi, Syi) because i need the to find the Centroid, which is correct.

I'm using Steiner's theorem to find the moment of inertia.

Please help me, i'm driving nutts...

I can scan my calculus so you can see what i am doing wrong but it won't do you much because it's kind of messy. (if you still would like to see it, just ask)

Thanks in advance. :)

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# Homework Help: Moment Of Inertia

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