| |
Main
Date: 12 Dec 2006 08:50:51
From: neo
Subject: Centrifugal force acting on runners in circular lane.
|
2 days ago I was watching asiad running competetion. I think
competitions like this held on circular tracks are not fair. The runner
in inner lane has to resist centrifugal force more than the runners in
outer lanes. I think it affects performance of runner running on inner
track. Also the runner in inner track 'see' that other runners are far
ahead of him. Although it is not mathematically true, but it gives
psychological advantage to runners in outer lanes and affect moral of
runners in inner lanes.
If I am right, runner on inner track seldom wins.
So such competitions are unfair.
|
|
| |
Date: 12 Dec 2006 09:50:29
From: Randy Poe
Subject: Re: Centrifugal force acting on runners in circular lane.
|
neo wrote:
> 2 days ago I was watching asiad running competetion. I think
> competitions like this held on circular tracks are not fair. The runner
> in inner lane has to resist centrifugal force more than the runners in
> outer lanes. I think it affects performance of runner running on inner
> track. Also the runner in inner track 'see' that other runners are far
> ahead of him. Although it is not mathematically true, but it gives
> psychological advantage to runners in outer lanes and affect moral of
> runners in inner lanes.
>
> If I am right, runner on inner track seldom wins.
>
> So such competitions are unfair.
It's interesting that in speed skating they seem more sensitive to
this than running. Heats pair two skaters at a time (I can't remember
if finals do or not), and the skaters change lanes back and
forth at specific points.
Perhaps somebody found, or believes, that the greater velocities
in skating give more of a difference between lanes.
- Randy
|
| | |
Date: 12 Dec 2006 21:34:05
From: Harold Buck
Subject: Re: Centrifugal force acting on runners in circular lane.
|
In article <1165945829.668470.181620@l12g2000cwl.googlegroups.com >,
"Randy Poe" <poespam-trap@yahoo.com > wrote:
>
> It's interesting that in speed skating they seem more sensitive to
> this than running. Heats pair two skaters at a time (I can't remember
> if finals do or not), and the skaters change lanes back and
> forth at specific points.
>
This could also be to keep from having to stagger the start (and so
people can get a better idea which person is in front).
For the 500m, IIRC, they skate it twice, with each starting once on the
inner and once on the outer. I think it's harder to start on one or the
other, so they balance it out for the 500m.
--Harold Buck
"Hubris always wins in the end. The Greeks taught us that."
-Homer J. Simpson
|
| | |
Date: 12 Dec 2006 19:49:36
From: CWatters
Subject: Re: Centrifugal force acting on runners in circular lane.
|
"Randy Poe" <poespam-trap@yahoo.com > wrote in message
news:1165945829.668470.181620@l12g2000cwl.googlegroups.com...
> It's interesting that in speed skating they seem more sensitive to
> this than running. Heats pair two skaters at a time (I can't remember
> if finals do or not), and the skaters change lanes back and
> forth at specific points.
and in longer track events they don't use lanes.
I heard some people like the inside lane because it gives them someone to
chase.
|
| |
Date: 12 Dec 2006 09:27:17
From:
Subject: Re: Centrifugal force acting on runners in circular lane.
|
shipmodeler1 wrote:
> Interesting. When you've gathered some data on this get back to us.
Google picked this up
Statistical Effects of Lane Allocation on Times in Running Races
R. Hugh Morton
Statistician, Vol. 46, No. 1 (1997), pp. 101-104
it's on JSTOR and I don't have access.
|
| | |
Date: 12 Dec 2006 10:51:05
From: Beginning runner
Subject: Re: Centrifugal force acting on runners in circular lane.
|
In article <1165944437.019215.86800@l12g2000cwl.googlegroups.com >,
simohunt@hotmail.com wrote:
> Google picked this up
>
> Statistical Effects of Lane Allocation on Times in Running Races
> R. Hugh Morton
> Statistician, Vol. 46, No. 1 (1997), pp. 101-104
>
> it's on JSTOR and I don't have access.
It says that lane 8 has about a 1 meter advantage over lane 1 in a 200
meter race--about .04 seconds.
|
| | | |
Date: 13 Dec 2006 00:59:19
From: steve common
Subject: Re: Centrifugal force acting on runners in circular lane.
|
Beginning runner <beginning_runner@cox.net > wrote:
>It says that lane 8 has about a 1 meter advantage over lane 1 in a 200
>meter race--about .04 seconds.
There you go. I almost recalled correctly :-)
|
| |
Date: 12 Dec 2006 09:10:47
From: shipmodeler1
Subject: Re: Centrifugal force acting on runners in circular lane.
|
Interesting. When you've gathered some data on this get back to us.
|
| |
Date: 13 Dec 2006 00:58:34
From: steve common
Subject: Re: Centrifugal force acting on runners in circular lane.
|
"neo" <MATREEX@gmail.com > wrote:
>The runner
>in inner lane has to resist centrifugal force more than the runners in
>outer lanes. I think it affects performance of runner running on inner
>track.
The force is stronger, but he doesn't have to put up with it as long as
the guy in the outer lane (on an eight lane track that's pi/2*7*lane width
further round one curve = >10*lane width further). So IIRC the inner lane
has been calculated to be mechanically easier than the outer lanes, to the
tune of a few centimeters/hundredths of a sec.
So if inner lane runners really aren't winning enough, either it's purely
a statistical fluke, or the psycological side you mention is far more
important.
|
| |
Date: 12 Dec 2006 20:49:53
From: Daniel-San
Subject: Re: Centrifugal force acting on runners in circular lane.
|
"neo" wrote ...
>centrifugal force
You misspelled "inertia."
Dan
|
| |
Date: 13 Dec 2006 00:10:43
From: Bucky
Subject: Re: Centrifugal force acting on runners in circular lane.
|
steve common wrote:
> The force is stronger, but he doesn't have to put up with it as long as
> the guy in the outer lane (on an eight lane track that's pi/2*7*lane width
> further round one curve = >10*lane width further).
Why would the inner lane runner have less curved track to cover? The
start is staggered with the inside runner further back... the exact
same length as the outer runner.
Or another way to think about it: the race is the same distance for all
runners, and the straightaways are the same distance. Therefore the
curved distances must all be the same too.
|
| | |
Date: 14 Dec 2006 02:16:09
From: Mark and Christine
Subject: Re: Centrifugal force acting on runners in circular lane.
|
> steve common wrote:
> Why would the inner lane runner have less curved track to
> cover? The start is staggered with the inside runner
> further back... the exact same length as the outer runner.
>
> Or another way to think about it: the race is the same
> distance for all runners, and the straightaways are the
> same distance. Therefore the curved distances must all be
> the same too.
If you don't think of it as time on the curve (due to the
stager) and instead think of it as the distance run to cover
the 180 arc, then the runner on the outside lane will change
direction slower than the runner on the inside - he will run
farther while turning the same amount as the inside runner.
Since any energy expended changing direction can not be used
to go toward the finish line, and changing direction faster
used more energy, the runner on the inside is at a mechanical
disadvantage.
If you are having trouble sleeping...
http://www-
mcnair.berkeley.edu/99mcnairjournal/campbell/campbell.html
Skip to the end where it states "Discussion."
|
| |
Date: 14 Dec 2006 00:24:29
From: Bucky
Subject: Re: Centrifugal force acting on runners in circular lane.
|
Mark and Christine wrote:
> Since any energy expended changing direction can not be used
> to go toward the finish line, and changing direction faster
> used more energy, the runner on the inside is at a mechanical
> disadvantage.
sure, I understand that. But Steve was trying to say that the inside
runner had a mechanical advantage (because they had less curved
distance to cover).
|
| | |
Date: 15 Dec 2006 01:05:41
From: steve common
Subject: Re: Centrifugal force acting on runners in circular lane.
|
"Bucky" <uw_badgers@email.com > wrote:
>But Steve was trying to say that the inside
>runner had a mechanical advantage (because they had less curved
>distance to cover).
I did indeed say that, and was about to throw in the towel, thinking I'd
got it all upside down, but then I looked at the cited paper.
They measured very tight curves, with radii of 1 to 6 meters (or did I get
that wrong too)? So OK I accept all you have said, on a track with a 1-6
meter radius curve. But I wonder if such exists in the wild? :oP
I will try to remember to look up the paper I read, which was of the same
style as the one under discussion, because it provided the conclusion I
stupidly (cos I don't remember the details) posted.
I still think that what I'm saying has been demonstrated, but I sure as
hell ain't convinced that I'm "right" - I may well have the whole thing
tits-upwards, ie the conclusion is "outer lane is favorised" but I won't
know til I found the blasted thing...
|
| | | |
Date: 15 Dec 2006 01:24:07
From: Mark and Christine
Subject: Re: Centrifugal force acting on runners in circular lane.
|
steve common <steven.common@wanadoo.fr > wrote in
news:fso3o29hh670op8dg83t0jp4j4olk43fc1@4ax.com:
> "Bucky" <uw_badgers@email.com> wrote:
>
>>But Steve was trying to say that the inside
>>runner had a mechanical advantage (because they had less
>>curved distance to cover).
>
> I did indeed say that, and was about to throw in the towel,
> thinking I'd got it all upside down, but then I looked at
> the cited paper.
The paper studied tight turns because they cause the largest
effect and therefore the effect is easier to measure. It
doesn't change the physics if you increase the diameter of the
curve - the effect is the same - the tighter the curve the
harder it is to run fast. Watch a college or above track
meet. If there is an empty lane it is always the inside lane.
The top runners on the track will always select the middle to
outside lanes.
Someone earlier in the thread commented about speed skating
and how they cross lanes every lap. That is because the
distance around the track compared to the distance of the race
is so short that a fair stager would be on the order of laps,
not meters, which would negate the head to head competition.
Christine
|
| | | | |
Date: 15 Dec 2006 09:11:09
From: Harold Buck
Subject: Re: Centrifugal force acting on runners in circular lane.
|
In article <Xns9899CF8B9D09EMailmailcom@69.28.186.158 >,
Mark and Christine <Mail@mail.com > wrote:
> Someone earlier in the thread commented about speed skating
> and how they cross lanes every lap. That is because the
> distance around the track compared to the distance of the race
> is so short that a fair stager would be on the order of laps,
> not meters, which would negate the head to head competition.
The fact that speed skating is basically done as a time trial also
eliminates the head-to-head competition. I think they just do two people
at a time so it looks like head-to-head competition, but how often are
the top two skaters going head-to-head?
--Harold Buck
"Hubris always wins in the end. The Greeks taught us that."
-Homer J. Simpson
|
| |
Date: 14 Dec 2006 19:57:44
From: The Ghost In The Machine
Subject: Re: Centrifugal force acting on runners in circular lane.
|
In sci.physics, neo
<MATREEX@gmail.com >
wrote
on 12 Dec 2006 08:50:51 -0800
<1165942251.079366.273200@f1g2000cwa.googlegroups.com >:
> 2 days ago I was watching asiad running competetion. I think
> competitions like this held on circular tracks are not fair. The runner
> in inner lane has to resist centrifugal force more than the runners in
> outer lanes. I think it affects performance of runner running on inner
> track. Also the runner in inner track 'see' that other runners are far
> ahead of him. Although it is not mathematically true, but it gives
> psychological advantage to runners in outer lanes and affect moral of
> runners in inner lanes.
>
> If I am right, runner on inner track seldom wins.
>
> So such competitions are unfair.
>
The world's fastest man runs 100 m in 10.6 seconds;
this is a velocity of about 10 m/s if one rounds up.
A little digging and ...
http://www.usatf.org/about/rules/2006/
Article III details track specifications in Rule 160; the
radius is a minimum of 24m (and only if it's a "double-bend
track", which negates the advantage of the inner track).
Assuming a weight of 60 kg, that gives a centripetal force of
(60 * 10^2) / 24 = 250N, less than half of the 588N from straight
gravity.
If one has a pure circular track, the radius is a minimum
of 35m, which gives a centripetal force of 171.5 N or 0.29 g.
An ideal track has 8 lanes each of width 1.22m; an outer
track would therefore have a radius of 43.54m and a
centripetal force of 137.8 N, or 0.23 g.
In theory, anyway.
--
#191, ewill3@earthlink.net
If your CPU can't stand the heat, get another fan.
--
Posted via a free Usenet account from http://www.teranews.com
|
| |
Date: 14 Dec 2006 21:52:52
From: Robert Grumbine
Subject: Re: Centrifugal force acting on runners in circular lane.
|
In article <1165942251.079366.273200@f1g2000cwa.googlegroups.com >,
neo <MATREEX@gmail.com > wrote:
>2 days ago I was watching asiad running competetion. I think
>competitions like this held on circular tracks are not fair. The runner
>in inner lane has to resist centrifugal force more than the runners in
>outer lanes. I think it affects performance of runner running on inner
>track. Also the runner in inner track 'see' that other runners are far
>ahead of him. Although it is not mathematically true, but it gives
>psychological advantage to runners in outer lanes and affect moral of
>runners in inner lanes.
>
>If I am right, runner on inner track seldom wins.
Put me on the track next to a real sprinter and it certainly won't
matter which lanes we're in.
Let's look at some numbers. (Though I dropped it, the original was
x-posted to sci.physics.)
Suppose we have a track which is 100 m on the straights, and 100m
semicircles on the curve in lane 1, with lanes 1 m wide.
The acceleration of a runner around that curve (v^2/r, r = 2*100/(2pi)
which comes out to 31.8 meters) at 10 meters per second (a good
sprint speed) is 3.14 m/s^2. Rather surprisingly high, and perhaps
I missed a constant of proportionality or two. This will turn out
not to matter.
Now consider the runner in lane 8, 7 lanes farther out. This lane
has a distance around the 1 turn of 100 + 7 pi meters, cranking out
to a radius of 38.8 meters. The acceleration experienced by the same
10 m/s sprinter is now reduced to 2.57 m/s^2, for a loss of 18%. The
18% figure is independant of those possibly lost constants of
proportionality.
If the argument is that the acceleration is the limiter, then
the runner in lane 1 must slow down by enough to drop v^2/r by 18%,
which means a 9% loss in speed. The runners are going the same
straight distance (which we've taken to be 100m, though it's typically
less, for simplicity). So, 10 m/s by the lane 8 runner for a 20 second
200m. The lane 1 runner takes the same 10 seconds on the straight,
but must run only 9.1 m/s on the curve, taking 11.0 seconds and
getting absolutely clobbered by the lane 8 guy. Lane 1 takes 21 seconds
to 20 seconds for lane 8, losing by 10 meters.
We observe, however, that real sprinters of closely matched abilities
finish 200 m races close to each other. The guy who won his heat in
20.2 from lane 4 and gets seeded to lane 4 finishes about the same 0.2
seconds ahead of the guy who scraped in to the final with a 20.4 from
lane 4 and is in lane 8 or 1. If the above consideration were correct,
the 20.4 second runner seeded into lane 8 should cream the guy in lane
4 even though he's the slower runner.
So this isn't the right consideration.
The psychological considerations ... well, that depends on the
psychology of the runners involved. I once intentionally lined up
so that I _couldn't_ see the guy I was racing (I race better from
in front), while he intentionally lined up so that he _could_ see
me. (Stampede lane assignment, so I wound up in 2 or 3 and he was
in 6 or 7.) We talked about it afterwards is how I know his
intentions.
... Having written the preceding, now I have to go track down
the JSTOR article mentioned. I have some access to that, hopefully
enough.
>So such competitions are unfair.
--
Robert Grumbine http://www.radix.net/~bobg/ Science faqs and amateur activities notes and links.
Sagredo (Galileo Galilei) "You present these recondite matters with too much
evidence and ease; this great facility makes them less appreciated than they
would be had they been presented in a more abstruse manner." Two New Sciences
|
| |
Date: 15 Dec 14:47:46
From:
Subject: Re: Centrifugal force acting on runners in circular lane.
|
In article <1166189064.123635.5870@16g2000cwy.googlegroups.com >,
"Edward Green" <spamspamspam3@netzero.com > wrote:
>steve common wrote:
>
>> "neo" <MATREEX@gmail.com> wrote:
>>
>> >The runner
>> >in inner lane has to resist centrifugal force more than the runners in
>> >outer lanes. I think it affects performance of runner running on inner
>> >track.
>>
>> The force is stronger, but he doesn't have to put up with it as long as
>> the guy in the outer lane (on an eight lane track that's pi/2*7*lane width
>> further round one curve = >10*lane width further). So IIRC the inner lane
>> has been calculated to be mechanically easier than the outer lanes, to the
>> tune of a few centimeters/hundredths of a sec.
>
>The relative benefit of magnitude of the force vs. time would depend in
>detail on the dynamics of the runner, and probably vary in individuals.
>
>
>The solution is obviously to build figure-8 running tracks with
>fly-overs. Federal agencies should require all schools, however poor,
>to either build such a track or not use one at all, because of the
>deleterious psychological effect of lane bias.
How are you going to keep things equal when one contestent
gets to use the center lane? Are you going to have the
Federal agencies design intertwining figure eights for all
lanes? I suppose one would have to teach the Feds about Mobius
strips....<sniff >Do I detect a volunteer to teach them? ;-)
/BAH
|
| |
Date: 15 Dec 2006 05:24:24
From: Edward Green
Subject: Re: Centrifugal force acting on runners in circular lane.
|
steve common wrote:
> "neo" <MATREEX@gmail.com> wrote:
>
> >The runner
> >in inner lane has to resist centrifugal force more than the runners in
> >outer lanes. I think it affects performance of runner running on inner
> >track.
>
> The force is stronger, but he doesn't have to put up with it as long as
> the guy in the outer lane (on an eight lane track that's pi/2*7*lane width
> further round one curve = >10*lane width further). So IIRC the inner lane
> has been calculated to be mechanically easier than the outer lanes, to the
> tune of a few centimeters/hundredths of a sec.
The relative benefit of magnitude of the force vs. time would depend in
detail on the dynamics of the runner, and probably vary in individuals.
The solution is obviously to build figure-8 running tracks with
fly-overs. Federal agencies should require all schools, however poor,
to either build such a track or not use one at all, because of the
deleterious psychological effect of lane bias.
|
| | |
Date: 15 Dec 2006 12:31:47
From:
Subject: Re: Centrifugal force acting on runners in circular lane.
|
In article <1166189064.123635.5870@16g2000cwy.googlegroups.com >, "Edward Green" <spamspamspam3@netzero.com> writes:
> The solution is obviously to build figure-8 running tracks with
> fly-overs. Federal agencies should require all schools, however poor,
> to either build such a track or not use one at all, because of the
> deleterious psychological effect of lane bias.
Simpler...
Put magnets in the runner's shorts and a tall magnetic mono-pole at
the center of the curves at each end of the track. [Pun intended]
Or...
Use a Cavorite gravity shield and have them run on a cylindrical
track under their own self-induced centrifugal force.
|
| | | |
Date: 15 Dec 2006 21:04:14
From: The Ghost In The Machine
Subject: Re: Centrifugal force acting on runners in circular lane.
|
In sci.physics, briggs@encompasserve.org
<briggs@encompasserve.org >
wrote
on 15 Dec 2006 12:31:47 -0600
<Vm5mEK9zE3no@eisner.encompasserve.org >:
> In article <1166189064.123635.5870@16g2000cwy.googlegroups.com>, "Edward Green" <spamspamspam3@netzero.com> writes:
>> The solution is obviously to build figure-8 running tracks with
>> fly-overs. Federal agencies should require all schools, however poor,
>> to either build such a track or not use one at all, because of the
>> deleterious psychological effect of lane bias.
>
> Simpler...
>
> Put magnets in the runner's shorts and a tall magnetic mono-pole at
> the center of the curves at each end of the track. [Pun intended]
>
> Or...
>
> Use a Cavorite gravity shield and have them run on a cylindrical
> track under their own self-induced centrifugal force.
An interesting idea that, but I don't think H. G. Wells
was quite specific enough in the recipe for formation of
the substance... :-)
--
#191, ewill3@earthlink.net
Useless C++ Programming Idea #8830129:
std::set<... > v; for(..:iterator i = v.begin(); i != v.end(); i++)
if(*i == thing) {...}
--
Posted via a free Usenet account from http://www.teranews.com
|
| |
Date: 14 Dec 2006 22:57:13
From: Bucky
Subject: Re: Centrifugal force acting on runners in circular lane.
|
The Ghost In The Machine wrote:
> The world's fastest man runs 100 m in 10.6 seconds;
> this is a velocity of about 10 m/s if one rounds up.
Um... if you're stuck in the year 1912. The current 100m is 9.77s.
Although still 10 m/s if you round.
http://en.wikipedia.org/wiki/World_Record_progression_100_m_men
|
| | |
Date: 15 Dec 2006 21:03:10
From: The Ghost In The Machine
Subject: Re: Centrifugal force acting on runners in circular lane.
|
In sci.physics, Bucky
<uw_badgers@email.com >
wrote
on 14 Dec 2006 22:57:13 -0800
<1166165833.106296.44060@16g2000cwy.googlegroups.com >:
> The Ghost In The Machine wrote:
>> The world's fastest man runs 100 m in 10.6 seconds;
>> this is a velocity of about 10 m/s if one rounds up.
>
> Um... if you're stuck in the year 1912. The current 100m is 9.77s.
> Although still 10 m/s if you round.
>
> http://en.wikipedia.org/wiki/World_Record_progression_100_m_men
>
Interesting. I'll admit I plucked the first or second page
I found using a Google search; perhaps I misread it.
--
#191, ewill3@earthlink.net
Useless C++ Programming Idea #8830129:
std::set<... > v; for(..:iterator i = v.begin(); i != v.end(); i++)
if(*i == thing) {...}
--
Posted via a free Usenet account from http://www.teranews.com
|
| |
Date: 15 Dec 2006 20:39:33
From: Edward Green
Subject: Re: Centrifugal force acting on runners in circular lane.
|
jmfbahciv@aol.com wrote:
> In article <1166189064.123635.5870@16g2000cwy.googlegroups.com>,
> "Edward Green" <spamspamspam3@netzero.com> wrote:
> >The solution is obviously to build figure-8 running tracks with
> >fly-overs. Federal agencies should require all schools, however poor,
> >to either build such a track or not use one at all, because of the
> >deleterious psychological effect of lane bias.
>
> How are you going to keep things equal when one contestent
> gets to use the center lane? Are you going to have the
> Federal agencies design intertwining figure eights for all
> lanes? I suppose one would have to teach the Feds about Mobius
> strips....<sniff>Do I detect a volunteer to teach them? ;-)
Ah... you would think of that.
|
|
