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Groups > sci.physics.relativity > #375037
| From | Odd Bodkin <bodkinodd@gmail.com> |
|---|---|
| Newsgroups | sci.physics.relativity |
| Subject | Re: Car decelerates... |
| Date | 2016-01-28 09:59 -0600 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <n8dds5$17lg$1@gioia.aioe.org> (permalink) |
| References | (1 earlier) <b210245d-8d34-4ccd-8d45-8c5ab00cbbc8@googlegroups.com> <b8442691-e540-406d-87cb-eed7257df044@googlegroups.com> <ad413dcb-ae00-4a73-bf93-08a9e0fc564c@googlegroups.com> <56023379-d03f-40ca-a334-963a144716f4@googlegroups.com> <a640ff54-4f65-4939-9f88-b19f12803fc1@googlegroups.com> |
On 1/28/2016 1:34 AM, Jon Price wrote: > Well, Einstein considered it this way I believe. > > Scenario is like this... > Car is moving let's say w constant velocity with respect to road initially. > Then car decelerates. As we know (I think), drivers body moves forward. > > Now, same scenario but consider cars reference frame to be at rest. > What "causes" drivers body to move forward? > The frame of reference where the car is at rest is not an inertial reference frame. Since the car is decelerating and not in uniform motion, the frame that moves along with it is not in uniform motion either. This reference frame is thus a non-inertial reference frame. In non-inertial reference frame, mysterious "forces" without causes can appear. More accurately, in an non-inertial reference frame, the Newtonian laws of physics that you have ingrained in your head don't work any more. For example, those laws of physics say that something doesn't accelerate unless there is a net force acting on it; that something with no net force acting on it won't accelerate; and that an object's acceleration is proportional to the net applied force. So if you see the body move forward in this frame, the TEMPTATION is to apply Newton's laws and say, "Well, there must have been some force that caused that change in motion." But the thing is, Newton's laws don't apply well in this frame, and so your inference is mistaken. There is in fact no force that causes the body to move forward. As you know, what's really going on here is that the seat applies a force to your legs (friction) to get your legs to slow down with the car. But you have a pivot at your hips and there is no force between your seat and your upper body that could decelerate your upper body, and so your upper body does not decelerate the way your legs do. -- Odd Bodkin --- maker of fine toys, tools, tables
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Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 19:42 -0800
Re: Car decelerates... Melzzzzz <mel@zzzzz.com> - 2016-01-28 04:44 +0100
Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 19:48 -0800
Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-28 15:28 +1100
Re: Car decelerates... mlwozniak@wp.pl - 2016-01-27 22:58 -0800
Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-28 19:57 +1100
Re: Car decelerates... mlwozniak@wp.pl - 2016-01-28 01:07 -0800
Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-28 22:08 +1100
Re: Car decelerates... mlwozniak@wp.pl - 2016-01-28 03:51 -0800
Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-29 10:53 +1100
Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 19:31 -0800
Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 06:40 +0100
Re: Car decelerates... mlwozniak@wp.pl - 2016-01-28 22:29 -0800
Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 22:57 -0800
Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 08:08 +0100
Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 23:18 -0800
Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 08:24 +0100
Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-29 06:25 -0800
Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-29 10:19 -0800
Re: Car decelerates... Odd Bodkin <bodkinodd@gmail.com> - 2016-01-29 13:30 -0600
Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-29 12:21 -0800
Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-30 10:48 +0100
Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-31 13:55 +0100
Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-31 13:16 -0800
Re: Car decelerates... mlwozniak@wp.pl - 2016-01-29 00:35 -0800
Re: Car decelerates... Polikwaptiwa <polikw@polikwamail.org> - 2016-01-30 16:32 +0000
Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-30 18:02 -0800
Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 08:19 +0100
Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 23:23 -0800
Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 08:28 +0100
Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 23:39 -0800
Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-30 09:56 +0100
Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-30 10:09 +0100
Re: Car decelerates... Maciej Woźniak <mlwozniak@wp.pl> - 2016-01-30 11:34 +0100
Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-29 06:20 -0800
Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-29 23:12 +1100
Re: Car decelerates... Juan Sebastián <jseb@montserrat.info> - 2016-01-29 12:33 +0000
Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-30 22:16 +1100
Re: Car decelerates... Maciej Woźniak <mlwozniak@wp.pl> - 2016-01-30 12:25 +0100
Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-30 22:34 +1100
Re: Car decelerates... Maciej Woźniak <mlwozniak@wp.pl> - 2016-01-30 13:45 +0100
Re: Car decelerates... mlwozniak@wp.pl - 2016-01-29 04:42 -0800
Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-29 06:17 -0800
Re: Car decelerates... mlwozniak@wp.pl - 2016-01-29 06:23 -0800
Re: Car decelerates... Maciej Woźniak <mlwozniak@wp.pl> - 2016-01-29 06:17 +0100
Re: Car decelerates... Melzzzzz <mel@zzzzz.com> - 2016-01-28 13:37 +0100
Re: Car decelerates... moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-01-28 19:33 +0000
Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-27 20:08 -0800
Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 20:28 -0800
Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 20:34 -0800
Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-27 20:50 -0800
Re: Car decelerates... mlwozniak@wp.pl - 2016-01-27 23:00 -0800
Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 23:34 -0800
Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-28 07:23 -0800
Re: Car decelerates... Odd Bodkin <bodkinodd@gmail.com> - 2016-01-28 09:59 -0600
Re: Car decelerates... mlwozniak@wp.pl - 2016-01-28 22:27 -0800
Re: Car decelerates... Juan Sebastián <jseb@montserrat.info> - 2016-01-28 16:49 +0000
Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-28 22:29 +0100
Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-27 20:53 -0800
Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-28 07:47 +0100
Re: Car decelerates... Juan Sebastián <jseb@montserrat.info> - 2016-01-28 18:22 +0000
Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-28 22:31 +0100
Re: Car decelerates... Koobee Wublee <koobee.wublee@gmail.com> - 2016-01-27 23:59 -0800
Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 00:19 -0800
Re: Car decelerates... jamesl51165@gmail.com - 2016-01-28 08:18 -0800
Re: Car decelerates... Mike Fontenot <mlfasf@comcast.net> - 2016-01-28 09:46 -0700
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