Symmetric object prove principle axis goes through CM

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SUMMARY

The discussion centers on proving that any axis passing through the center of mass (CM) of a symmetric object is a principal axis. Participants reference the Displacement Axis Theorem and the tensor of inertia, which combines the properties of a stick and a disk. It is established that both geometries have principal axes aligned with the CM. The conversation emphasizes the mathematical proof required to substantiate this claim.

PREREQUISITES
  • Understanding of the Displacement Axis Theorem
  • Familiarity with the tensor of inertia
  • Knowledge of principal axes in rigid body dynamics
  • Basic principles of symmetry in physical objects
NEXT STEPS
  • Study the mathematical formulation of the Displacement Axis Theorem
  • Explore the derivation of the tensor of inertia for various shapes
  • Investigate the properties of principal axes in symmetric objects
  • Review examples of proving axes through the center of mass as principal axes
USEFUL FOR

This discussion is beneficial for physics students, mechanical engineers, and anyone studying rigid body dynamics, particularly those interested in the properties of symmetric objects and their principal axes.

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Homework Statement


c) For such a "symmetric" object, prove that any axis going through the center of mass is a principal axis.


Homework Equations


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The Attempt at a Solution



I am not sure how they want me to prove this. I was looking at the Displacement Axis Thm but I am not sure how to use it, or appropriate for this problem.

Thanks in advance.
 
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The tensor of inertial you have is a sum of that for a stick and that for a disk.
Each of these has all principal axes through the center.
 
Thank you for your reply,

Is there a way to prove this with math?
 

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