Angular momentum finding the principle axis

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SUMMARY

This discussion focuses on calculating the angular momentum of a cone rotating about its axis of symmetry while also rotating about the z-axis. It clarifies that every axis of symmetry is a principal axis, and the principal axes of a cone include its center line and all directions perpendicular to it. To determine angular momentum about the mass center G, one must first establish the angular velocity. If the angular velocity aligns with a principal axis, the angular momentum can be calculated by multiplying it by the moment of inertia; otherwise, the tensor method should be employed.

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SpartanG345
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If an object is rotating about the axis of symmetry
and you are trying to find the angular momentum about the mass centre g.

Does a rotation about the axis of symmetry correspond to a rotation about the principle axis?
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For this question i am trying to find the angular momentum about the mass centre of cone which is rotating about its axis of symmetry. However the axis of rotation is also rotating about the z axis.

Does the angular velocity w effect the angular momentum about the mass centre? I am guessing it would...

The only thing i am not sure about weather or not angular momentum about G would be evaluated about the principle axis
 
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Hi SpartanG345! :smile:

(btw, it's principal axis, like the principal of your school :wink:)
SpartanG345 said:
For this question i am trying to find the angular momentum about the mass centre of cone which is rotating about its axis of symmetry. However the axis of rotation is also rotating about the z axis.

Every axis of symmetry is a principal axis.

The principal axes of a cone are its centre line, and every direction perpendicular to that line.

To find the angular momentum, you must first find the angular velocity …

if that is along a principal axis, then just multiply by the moment of inertia; if not, then use the tensor method. :wink:
 

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