Angular Momentum: Axis of Rotation & Centre of Mass

AI Thread Summary
The discussion centers on the calculation of angular momentum (L) for a rigid body using the equation L = (moment of inertia) * (omega). It emphasizes that when the axis of rotation is moving, it must pass through the center of mass and be symmetrical for accurate calculations. In contrast, for a fixed and non-moving axis, it is not necessary for the axis to pass through the center of mass. The conversation also touches on the concept of a "natural" axis for free-spinning objects. Understanding these principles is crucial for accurately analyzing angular momentum in various scenarios.
glen_ky
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1) When we use the equation of L=(moment of inertia)*(omega) to calculate the angular momentum of a rigid body rotating around a moving axis, why the axis of rotation must pass through the centre of mass of this body and the axis should also be a symmetrical axis?

2) If for a fixed and non-moving axis, is this necessary to pass through the centre of mass?

Pls help, thanks.:eek:
 
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If someone could help...pls...Thanks...:frown:
 
Why nobody can help~~~how dissapointed...haizzzZzzzz...
 
Moving axis? How is the axis moving?

You can calcultate an angular momentum about any real fixed (relative to object) axis, but it the object is "free spinning", then it has a "natural" axis.

Maybe wiki will help here:

http://en.wikipedia.org/wiki/Angular_momentum
 

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