Timeline for Work-Energy Theorem vs Angular Momentum Conservation in Central-Force Problem
Current License: CC BY-SA 4.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Sep 13, 2020 at 0:37 | comment | added | Dale | @Ghost Repeater the slow decrease makes the KE from the radial component of velocity arbitrarily low, but it cannot reduce the work done decreasing the radius. | |
| Sep 12, 2020 at 7:21 | comment | added | gandalf61 | @GhostRepeater This is why it is important that the string is pulled gradually. if the string is pulled gradually then we are meant to assume that the radial velocity at any time is negligible compared to the tangential velocity. | |
| Sep 12, 2020 at 5:16 | comment | added | nothingIsMere | I foolishly left out part e) of the question, which I think is relevant to your explanation here. The authors state that the radius is stipulated to be decreased gradually specifically to keep the velocity (and hence the displacement) tangential. I see what you are saying though: there is just no way the mass can get from the larger radius to the smaller without radial displacement. However, wouldn't that mean the final kinetic energy would have a radial component of velocity in it? | |
| Sep 12, 2020 at 4:24 | history | answered | Dale | CC BY-SA 4.0 |