Moment of inertia for an irregular shaped object

AI Thread Summary
To calculate the moment of inertia for an irregular shaped object about its center of mass, the parallel axis theorem is applied incorrectly in this case. The initial calculation mistakenly uses the moment of inertia about a parallel axis instead of solving for the centroid's moment of inertia. The correct approach requires determining the moment of inertia about the center of mass directly, rather than adding the contributions from the parallel axis. The discussion highlights the importance of correctly identifying the reference point when applying the theorem. Clarification and further learning resources, such as MATLAB, are suggested for better understanding.
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An irregular shaped object of mass 2.45 kg has a moment of inertia 5.782 kgm2 about an axis through a point 1.40 m from its center of mass. Calculate the moment of inertia about a parallel axis through its center of mass.

I used the parallel axis theorem,
I= I_c + Mh^2
I= 5.782 +(2.45)(1.40)^2
I= 10.6 kgm^2

This wasn't right.. can someone tell me what I'm doing wrong. Thanks
 
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You are asked for the moment of inertia about the centroid, yet you are calculating the moment of inertia about a parallel axis to the centroid axis...
 
I_c is not 5.782, I_C is what your solving for.

I just got beaten to it. Have fun cyclovenom, I am going back to learning matlab.
 
ok I got it.. thanks
 
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