Thread View: bit.listserv.physhare
3 messages
3 total messages
Started by John Mallinckrodt
Thu, 11 May 1995 00:00
Re: Forces
Author: John Mallinckrodt
Date: Thu, 11 May 1995 00:00
Date: Thu, 11 May 1995 00:00
14 lines
909 bytes
909 bytes
Mervin Koehlinger writes: >Now we're getting to the heart of the matter. It's not individual forces >that produce rotation, but couples! > >Forces produce translation; couples produce rotation. Sorry, that does not compute. A rod in "free space" will be set into rotation by a SINGLE force as long as that force is not applied along a line that passes through the rod's center of mass. John Mallinckrodt Cal Poly Pomona ajmallinckro@csupomona.edu
Re: Forces
Author: Matt Tuley
Date: Thu, 11 May 1995 00:00
Date: Thu, 11 May 1995 00:00
32 lines
1630 bytes
1630 bytes
In article <9505112012.AA08777@csupomona.edu> John Mallinckrodt <ajmallinckro@CSUPOMONA.EDU> writes: >Mervin Koehlinger writes: >>Now we're getting to the heart of the matter. It's not individual forces >>that produce rotation, but couples! >> >>Forces produce translation; couples produce rotation. >Sorry, that does not compute. A rod in "free space" will be set into >rotation by a SINGLE force as long as that force is not applied along >a line that passes through the rod's center of mass. >John Mallinckrodt Right, that's it. As to the football player: I believe the original example of the football player had this player "flying" through the air, not touching ground or players or anything. If he's not already rotating, he won't start rotating. To get him rotating, something has to hit his feet (or his head, or anything not along a line with his CM--and gravity or not, friction or not, he _will_ start rotating). Hit 'em hard enough and eventually you'll be able to order it on a videotape some Sunday afternoon for only $19.95 so ACT NOW! ;) Matt Tuley tuley@csn.org Making my own little dent in the infinite Spandex of the universe...
Re: Forces
Author: Guntbert Reiter
Date: Mon, 15 May 1995 00:00
Date: Mon, 15 May 1995 00:00
31 lines
1532 bytes
1532 bytes
John Mallinckrodt <ajmallinckro@CSUPOMONA.EDU> wrote: >Mervin Koehlinger writes: >>Now we're getting to the heart of the matter. It's not individual forces >>that produce rotation, but couples! >> >>Forces produce translation; couples produce rotation. I prefer: Forces cause acceleration (not necessarily movement) while couples cause a torque (not a rotation). >Sorry, that does not compute. A rod in "free space" will be set into >rotation by a SINGLE force as long as that force is not applied along >a line that passes through the rod's center of mass. John: It DOES compute. Imagine the impact resulted in pure movement without rotation. More exactly spoken: the result would be a linear acceleration of the CM. By Newton's laws (inertia...) we know that from this acceleration the CM should "feel" (I just can't remember the correct term) a corresponding force pointing in the opposite direction. So these two forces build a couple and produce a torque. bye, bye Guntbert ------------------------------------------------ Guntbert Reiter : guntbert@borg-6.borg-graz.ac.at HTL Weiz Graz Austria
Thread Navigation
This is a paginated view of messages in the thread with full content displayed inline.
Messages are displayed in chronological order, with the original post highlighted in green.
Use pagination controls to navigate through all messages in large threads.
Back to All Threads