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is angular accelaration or angular velocity about an axis passing through COM same as that of angular acceleration about any other axis passing through the same body?

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The answer is no.

Short argument: Angular velocity and angular accelaration are vectors, they have a magnitude and a direction. When you measure the component of a vector (for example angular velocity) along a generic axis, you are measuring the projection of the vector over said axis. The angular velocity is maximum in the axis parallel to the vector's direction, and zero in any axis perpendicular to the vector.

Example: Take the motion of Earth around the Sun as an example. The COM is roughly located at the center of the Sun. The angular velocity respect to the axis normal to the plane of motion is $\omega_z=v/R$, where $v$ is the velocity and $R$ the distance from Earth to the axis of rotation (the distance to the Sun).

However, if we calculate the angular velocity repect to an axis inside the plane of motion, we will obtain that it is equal to zero ($\vec{v}_t=\vec{r}\times\vec{\omega}$, so project $\vec{\omega}$ over said axis if you don't see it).

The angular accelaration is the time derivative of the angular velocity, so it will be also different in the general case.

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  • $\begingroup$ Are you sure about this? $\endgroup$ – FGSUZ Feb 13 '19 at 22:03
  • $\begingroup$ Did my edit convince you or you do think that there is something wrong in my reasoning? $\endgroup$ – TheAverageHijano Feb 14 '19 at 6:40

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