Is it necessary to calculate the moment fulcrum without rotation?

Is it necessary to calculate the moment fulcrum without rotation?

For example, an object rotating in the air
The results of physical problems have nothing to do with the selection of coordinate system
But the final interpretation should be consistent
It's just that different coordinate systems may have different processing methods
Generally, the system that is more convenient to handle the problem will be selected
This discussion area has discussed the problem of cylinder rolling down an inclined plane
The center axis of the cylinder can be selected, and the contact point between the cylinder and the inclined plane can also be selected as the rotation center
The calculated moments are different, but the final results are the same
Of course, it's not impossible to select other points on the cylinder, it's just to add the complexity of mathematical processing
What's better if the fulcrum doesn't rotate? There's no static moment~
Think about what you're asking first
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Just a passing student
Take the center of mass of the object as the fulcrum and any point as the fulcrum, refer to the chapter of pure rolling on the inclined plane + spring or university general physics rotation