Rotation around center of mass principle

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When a torque is applied to a free object, it rotates around its center of mass due to the principle of least energy, as this position minimizes energy expenditure. This behavior is linked to the stability of rotation; rotating around the center of mass is more stable compared to other axes, which can lead to instability. The discussion highlights that the center of mass serves as a natural pivot point, ensuring efficient motion. The concept of rotational dynamics emphasizes that systems tend to favor configurations that require less energy. Understanding this principle is crucial for analyzing the behavior of rotating bodies in physics.
arto460
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Hey all!
I always use this principle when I do exercises, but today I found out, that I can't explain why it's valid. What I'm talking about is that when you apply a torque to a free object it will always start to rotate around it's center of mass rather than just an arbitrary point. Why is that? I know that rotation around the cm requires the least energy so if there was some fundamental theorem saying that a system always tends towards the least increase in energy or whatever, that might explain it.
Yet I don't think that's the way to go, so can someone explain it please?
 
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I never really questioned it myself but I think it has to do with rotation about the center of mass being the most stable position. Otherwise rotating about another axis (which is not the center of mass) usually causes high instability.

An example is rotating unbalance.
 

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