Timeline for Acceleration of the center of mass without external forces paradox
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 15, 2021 at 16:56 | comment | added | manisar | You are welcome | |
| Jul 15, 2021 at 16:53 | comment | added | 00100 | It's very clear now. Thank you so much | |
| Jul 15, 2021 at 16:45 | comment | added | manisar | So, even in the absence of external forces, it would still be possible for the athlete to do a few things to gain some advantage, e.g. he can orient his body in a way that without changing his COM, some of his body parts are higher (at the cost of other parts getting lower), and he gets more points in high jump. | |
| Jul 15, 2021 at 16:20 | comment | added | manisar | Yes, but though moving the COM of a body or system is not possible in the absence of external forces, orienting the body (parts of system) in different ways around the COM is definitely possible. See how astronauts can move parts of their body, but not the body as a whole - reddit.com/r/space/comments/77y7cc/astronaut_stuck_in_midair. Here, there is some movement of COM, because of the presence of air, and exhalation by the astronaut without which it would not be possible to move at all. Summary - you move one part, another part will move to compensate and keep the COM fixed! | |
| Jul 15, 2021 at 14:18 | comment | added | 00100 | topendsports.com/biomechanics/center-of-gravity.htm so such movements by athletes that change center of mass are impossible in the absence of external forces | |
| Jul 14, 2021 at 21:52 | comment | added | manisar | Ok, the above experiment is much better doable on two boats in water - one with the object and the other with the person pulling the object. | |
| Jul 14, 2021 at 21:50 | comment | added | manisar | On a smooth surface tie a rope to a heavy object (perhaps half your weight). Then hold the the other end of the rope and give a hard quick pull to the rope. If the surface is really smooth, you'll see that not only the object moves towards you, but you will also move towards the object. (...while I think of a better experiment). | |
| Jul 14, 2021 at 21:47 | comment | added | 00100 | That's sounds reasonable although have no idea how to verify it's true. | |
| Jul 14, 2021 at 21:47 | vote | accept | 00100 | ||
| Jul 14, 2021 at 21:43 | history | answered | manisar | CC BY-SA 4.0 |