Angular vel. and mom.-origins vs. axes

[TomServo]

Angular vel. and mom.--origins vs. axes

This is a conceptual question.

Angular velocity is measured with respect to an axis, correct?

Yet angular momentum is measured with respect to an origin, i.e. a point, correct?

For angular momentum problems where only the magnitude of angular momentum changes, it seemed like we were calculating L with respect to an axis, but that was not correct, strictly speaking, right?

 

[tiny-tim]

Hi TomServo!

This is a conceptual question.

Angular velocity is measured with respect to an axis, correct?

Yet angular momentum is measured with respect to an origin, i.e. a point, correct?

Angular velocity and angular momentum are both vectors (strictly, psuedovectors)

Angular momentum is measured wrt a point

Angular velocity isn't

For angular momentum problems where only the magnitude of angular momentum changes, it seemed like we were calculating L with respect to an axis, but that was not correct, strictly speaking, right?

Right! In that case, we are assuming (correctly) that the angular momentum lies along that axis, without bothering to say so!