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Groups > sci.physics > #597033
| From | Wally W. <ww84wa@aim.com> |
|---|---|
| Newsgroups | sci.physics |
| Subject | Re: Viewing the spokes |
| Date | 2016-09-15 09:15 -0400 |
| Organization | A noiseless patient Spider |
| Message-ID | <pf7ltb1c74llltola17oscbpnbouf13ath@4ax.com> (permalink) |
| References | <nq1q63$bdd$1@gioia.aioe.org> <4415adab-bce4-441b-a953-9ba8d36f5549@googlegroups.com> |
On Fri, 9 Sep 2016 09:08:14 -0700 (PDT), nuny@bid.nes wrote: >On Monday, August 29, 2016 at 10:08:25 AM UTC-7, Sergio wrote: >> Viewing the spokes >> >> A wheel with spokes rolls on the ground. A stationary camera takes a >> picture of the wheel. Due to the nonzero exposure time of the camera, >> the spokes will generally appear blurred. At what location(s) in the >> picture does (do) the spoke(s) not appear >> blurred? > >> >> answer, >> >> >> The contact point on the ground does not look blurred, because it is >> instantaneously at rest. > > There is no "instantaneous". The wheel *moves* while the shutter is open, hence the contact patch will move, hence the lowermost spokes will be blurred. > > Now, if you want to talk about which spokes will be *least* blurred... > > > Mark L. Fergerson Agreed, everything moves during the finite time the shutter is open. Still, "instant centers" is a well worn concept in kinematics: http://ocw.mit.edu/courses/mechanical-engineering/2-003j-dynamics-and-control-i-spring-2007/lecture-notes/lec08.pdf Figure 3: A disk with radius R rolls angular velocity omega in x-direction. Point I marks the contact with disk and ground: no slip, not moving for an instant because ground is still. Instant center.
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Viewing the spokes Sergio <invalid@invalid.com> - 2016-08-29 12:08 -0500
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-08-29 18:00 +0000
Re: Viewing the spokes benj <benj@nobody.net> - 2016-08-29 21:00 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-08-30 01:14 +0000
Re: Viewing the spokes benj <benj@nobody.net> - 2016-08-29 22:45 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-08-30 04:14 +0000
Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-29 21:59 -0700
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-08-30 05:16 +0000
Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-29 23:00 -0700
Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-08-29 18:29 -0700
Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-29 18:29 -0700
Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-29 18:46 -0700
Re: Viewing the spokes benj <benj@nobody.net> - 2016-08-30 19:40 -0400
Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-30 22:07 -0700
Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-30 23:48 -0700
Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-08-31 09:54 -0700
Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-09-02 10:00 -0700
Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-02 13:23 -0700
Re: Viewing the spokes The Starmaker <starmaker@ix.netcom.com> - 2016-09-03 11:30 -0700
Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-03 13:18 -0700
Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-03 14:57 -0700
Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-03 16:01 -0700
Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-04 12:46 -0700
Re: Red, Blue and Green Ergios <invalid@invalid.com> - 2016-09-07 12:32 -0500
Re: Red, Blue and Green noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-08 12:12 -0700
Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-07 23:22 -0700
Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-03 16:03 -0700
Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-03 16:06 -0700
Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-20 00:18 -0700
Re: Red, Blue and Green noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-20 12:52 -0700
Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-07 10:01 -0700
Re: Red, Blue and Green Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2016-09-07 10:12 -0700
Re: Red, Blue and Green The Starmaker <starmaker@ix.netcom.com> - 2016-09-20 09:47 -0700
Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-08-31 14:32 -0700
Re: Viewing the spokes "reber g=emc^2" <herbertglazier0@gmail.com> - 2016-09-04 11:39 -0700
Re: Viewing the spokes "hanson" <hanson@quick.net> - 2016-09-04 20:36 -0700
Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-09 09:08 -0700
Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-09 12:32 -0700
Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-09 17:51 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-10 00:10 +0000
Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-09 20:43 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-10 00:57 +0000
Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-09 21:07 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-10 01:33 +0000
Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-12 20:59 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-13 02:41 +0000
Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-09 19:43 -0700
Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-12 21:29 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-13 02:43 +0000
Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-13 13:28 -0700
Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-13 17:14 -0700
Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-13 21:52 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-14 05:11 +0000
Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-15 17:49 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-16 00:50 +0000
Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-15 21:52 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-16 04:11 +0000
Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-16 16:58 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-16 21:40 +0000
Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-16 20:56 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-17 01:47 +0000
Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-17 17:24 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-18 00:07 +0000
Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-14 14:26 -0700
Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-14 15:04 -0700
Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-16 12:54 -0700
Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-14 19:47 -0700
Re: Viewing the spokes benj <nobody@gmail.com> - 2016-09-14 23:24 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-15 05:12 +0000
Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-15 15:45 -0700
Re: Viewing the spokes benj <benj@nobody.net> - 2016-09-15 21:36 -0400
Re: Viewing the spokes jimp@specsol.spam.sux.com - 2016-09-16 02:58 +0000
Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-18 12:15 -0700
Re: Viewing the spokes Wally W. <ww84wa@aim.com> - 2016-09-15 09:15 -0400
Re: Viewing the spokes "nuny@bid.nes" <Alien8752@gmail.com> - 2016-09-15 15:48 -0700
Re: Viewing the spokes noTthaTguY <abu.kuanysh05@gmail.com> - 2016-09-18 15:33 -0700
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