Timeline for Angular velocity across different reference frames
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 7, 2021 at 7:36 | comment | added | Shay | Thank you very much :) This definitely answers my question! | |
| Oct 7, 2021 at 7:35 | vote | accept | Shay | ||
| Oct 5, 2021 at 11:17 | comment | added | Vasily Mitch | Yes, in non-relativistic mechanics the position of the CoM is the same in all frames, Thus $J_{CM}$ will be the same in all inertial frames. But importantly, when we calculate $J_CM$ we calculate it with respect to moving CoM with whatever the velocity it has in the given FoR. It's not a fixed point coinciding with the CoM at the given time. In other words, $J_CM$ is the angular momentum in the CoM FoR with respect to CoM. | |
| Oct 4, 2021 at 8:20 | comment | added | Shay | To clarify: if I calculate angular momentum with respect the CoM, then as you've shown, $J=I\omega$; but then if I change my reference frame but still calculate angular momentum with respect to the center of mass, then the velocity changes but the position of each body in the system with respect to the CoM remains unchanged. At the same time, we're still calculating with respect to the center of mass, and so $J=I\omega$ should still hold. This is the bit I'm confused about. | |
| Oct 4, 2021 at 8:17 | comment | added | Shay | Thanks a lot for your helpful & detailed answer! What I meant when I said I'm interested in changing the frame of reference is that I'll be changing it but not the point(/axis) w.r.t which I calculate the angular momentum. That is, I make a certain (misguided, perhaps?) distinction in my mind between the origin point of my reference/coordinate frame and the point w.r.t which I calculate angular momentum; so the position vector is invariant. Is this where my error lies? That is: if I calculate ang. momentum w.r.t CoM, then must the velocity also be calculated within the CoM reference frame? | |
| Oct 3, 2021 at 12:29 | history | answered | Vasily Mitch | CC BY-SA 4.0 |