To reraise an issue about COM: Should we really use the COM at standstill?
To me it seems to make more sense to use COM at the time the takeoff foot
looses contact with the ground. (This will depend on exactly how and when
speeds are measured, and whether the solecontacttotoecontact change
increases or decreases vertical speed.) I made a (very) approximate measurement on myself (also 6'2''6'3''), and saw roughly a 10 cm increase, which puts us
back at roughly 1.26.
Admittedly, the effect will likely be limited, but one or two extra decimeter
lengthwise seem plausible to me. (The projectile applet, unfortunately, crashes my browser.)
Similarly, armmovements may possibly raise the COM a few additional
centimeters.
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Carl Lewis 30ft Long Jump
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jrm has a 60m function in the dropdown menu of his 100m calc
try it out  6.50 with +1.0 > 6.523 basic ( i put in something wrong to get 6.49 basic )
take off 0.05s for poor rt & his likely at best 0.14s & you get 6.47, which i agree is same as dwight's
as for his top speed, i already mentioned 0.83s is likely to dip at takeoff to 0.84 or 0.85s, but this is still hugely quicker than 0.89s speed ( 11.2 ) & he even dipped from there to 0.904s speed as you quote
Carl LEWIS 8.91m
11.23 / 11.26 / 11.06 / 9.72 / 3.22
apply that to 0.83 & you still have 0.84  0.85 with slowing at takeoff, which is still helluva lot quicker than 0.904 speed
all it comes down to is what angle he gets with 0.84  0.85 speed  if he coud manage 11.5 degrees ( just over 1/2 of usual angle ), he'd get 9.00 with it
put it in yourself
http://www.walterfendt.de/ph11e/projectile.htm
poster on page 1 says we shoud use 1.16m for c o m
I think the centre of mass of 1.25 is a little bit to much. I thought centre of mass was about 0.6180 times height. so in Lewis case around 1.16
try 0.84 or 0.85 speed with that & see what angle is needed for 9.00
coud he have done 11.5 degrees ?
i think it's feasible
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Originally posted by eldrickas for indoor pbs, people have expressed scepticism at 6.02i  he never ever looked that fast for 60m
besides, that 6.46 split had a +1.2 wind overall for 100m  jrm has 60m calc ( he says if wind for 100m race is used for 60m split there is little more than 0.01s error ) > ~ 6.50s basic ( rome split is better at 6.49 basic )
However, his reaction time was terrible 0.196. This gives 6.30 without reaction time and 6.40 "basic" with perfect reaction time. With an average reaction time, he was able to run mid 6.4, which ties with his 6.02, 6.04, 6.06, 6.07 60 yards times, all worth about 6.456.50.
If he he was allowed to do flying starts in those 4 indoors races, he was allwoed to do so outdoors? I don't follow your logic.
Carl Lewis runup was 21 steps in Tokyo'91, but speed is recorded btw 1 and 11m to the board, so he is in the zone after 18 steps i guess. However, the is a reduction of speed on the 1 to 0m to the board, in ordert to prepare the jump and transfer horizontal speed into vertical speed. That's why your reasoning is false regarding Lewis using his 12m/s top speed into a jump. Body positions are different in sprinting and runup, same thing applies for Drechsler.
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last part is interesting ( to me's anyways ! )
say he did try a 60  70m run exclusively in a meet & did it 12 times in his career when he had exceptional speed ( '81  '93 )  i e 1 meet/year
you can't say he had no chance of "nailing" a jump ( he was of unique calibre ), just very little probability
trying different probabilities of nailing it in 1 meet & seeing what overall probability is of doing it at least once during 12 meets
1% > 1  0.99^12 = 11.3%
2% > 1  0.98^12 = 21.5%
3% > 1  0.97^12 = 30.6%
4% > 1  0.96^12 = 38.7%
5% > 1  0.95^12 = 45.9%
6% > 1  0.94^12 = 52.4%
so, if he had a 6% chance of 9.00m at any 1 meet with a 60  70m runup, then 12 meets in a career attempting such, means probability wouda been in his favor of jumping it
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Originally posted by PierreJeanIf you don't trust Lewis 6.02, then use 6.04 (in 1983, worth 6.476.48) or 6.06 (in 1981, worth 6.494.50). Phillip's next best ever is 6.53, do you doubt his 6.47?
The difference between Tomlinson and Lewis is that Lewis requires more distance to reach max speed (Tomlinson prolly 50m, Lewis 70m).
Your reasoning should apply to all jumpers, they all use shorter runs up than 50m, hence should all take longer runs up to reach max speed. Again, the problem is to transfer your sprint into a jump, hence all the jumpers have an approach speed during runup fractionnally slower than their max speed during sprints.
he was a slow starter & also likely reaction, so good chance he tried to catch a flyer in those american meets knowing little chance of being called back by starter who knew who the big draw was
in europe races, he never looked like a mid6.4 guy in his 100m races
dwight's 6.47i i have perfect faith in  RT equipment at hand to call a flyer  it obviously wasn't
as for runups  sure, they shoud try 60  70m ones, but as i said, you're only going to have enough energy to do 2 or 3 jumps out of 6 if you're running flatout 60m
likelihood is you may not not get in 1 valid jump out of 1st 3 attempts in a championship with this hit & miss approach  so basis of risk/reward, not a viable proposition there as you may not get a valid jump in initial 3 attempts
your also only likely to have 2 attempts out of initial 3 ( 1st & 3rd attempts ) as fullout sprinting for 60m isn't likely to let you recover for attempt 2
cutting runup to 50m means majority have submax speed at takeoff, but better control & likely to get a valid jump in, but not ultimate potential jump  the physics shows speed is better than angle
i've seen enough of his jumps & got bored with his runup, which for last 20m looked liked he was cruising the 130  150m section of a 200  not attacking the board with the ferocity of like a lebedeva
he had 0.83s speed & wasted it by never trying 60  70m runups
time to attempt it was not a championship, but a gp meet with 6 attempts guaranteed & knowing he was only going to put in 2 or 3 attempts, inform promoter this was going to be a hit & miss affair trying to see if coud "nail" an angle & be behind the board with one of his 2 or 3 attempts
bottom line 
 standard run up, he had 50%+ chance of a 8.50+ & obviously a likely win
 60m+ runup maybe gave him a 5  10% chance of a 9.00m jump in a meet  trying a dozen meets between '82  '92, woud give him mathematically a
~ 45  70% probability of a 9.00m jump
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My recollection is that Carl Lewis run up was about 170'/52m. I don't remember any of his contemporaries had a longer run up.
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If you don't trust Lewis 6.02, then use 6.04 (in 1983, worth 6.476.48) or 6.06 (in 1981, worth 6.494.50). Phillip's next best ever is 6.53, do you doubt his 6.47?
The difference between Tomlinson and Lewis is that Lewis requires more distance to reach max speed (Tomlinson prolly 50m, Lewis 70m).
Your reasoning should apply to all jumpers, they all use shorter runs up than 50m, hence should all take longer runs up to reach max speed. Again, the problem is to transfer your sprint into a jump, hence all the jumpers have an approach speed during runup fractionnally slower than their max speed during sprints.
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Originally posted by PierreJeanEldrick, i don't agree fully with the excellence at 50 or 60m for Long Jump...
you are also assuming that at peak speed of 12.0m/s he coudn't get the same takeoff angle  he probably woudn't, but it's not impossible  tomlinson himself states that he tries for absolute max speed at the board & jump off that  so that's one current elite guy who tries for max speed
i'd like to have seen him try with max speed  12m/s over 11.2m/s with same angle on a previous assumed 8.80pb yields over 9.40m  sure angle woud be less at max speed, but it may still have been good enough for 9.00+ with fractional slowing at takeoff to 0.84  0.85s speed & slightly less angle than at 0.89s
also no matter how you play it, if King's takeoff was only 50m, there is no way he was going to get max speed in such a short distance, starting blocks or not  he needed 60  70m to get upto 0.83s speed  whether lj runups can extend to 60  70m, i don't know  clearly he'd only have energy for 2 or 3 jumps out of 6 in such a scenario, but if he wanted the wr, that's what he needed to do
frankly, if you have 0.83s speed, you'd want to have a runup long enough to attempt to generate it & see if at least once, you "nail it" with that speed & reasonable angle  using 0.89s speeds always is a disappointment
as for indoor pbs, people have expressed scepticism at 6.02i  he never ever looked that fast for 60m
besides, that 6.46 split had a +1.2 wind overall for 100m  jrm has 60m calc ( he says if wind for 100m race is used for 60m split there is little more than 0.01s error ) > ~ 6.50s basic ( rome split is better at 6.49 basic )
dwight had faster 60m pb & also potential for 9.00+, but again, not long enough runway to get to top speed
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In a next step we can reason that CL could have received an even
larger speed increase by using a longer runup (than he could have
from dropping sprinting). Likely, then, he felt that he already had
all the speed he needed and could handle at takeoff.
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Eldrick, i don't agree fully with the excellence at 50 or 60m for Long Jump, since these distance require perfect execution with starting blocks, which is irrelevant for LJ. 50m with standing start, or the ability to generate highest speed over the shortest distance describes what is needed during a long jump approach. Lewis had his fastest runup speeds recorded at 11.0 to 11.2m/sec, which he was able to produce after about 16 to 18 steps, into a progressive acceleration. At 12m/sec (the speed he reached after roughly 30 to 35 steps during 100m races), Lewis couldn't be in proper position to create an impusle at the required angles.
Dwight Phillips' indoor PB 6.47 is no better than Carl Lewis' 60 yards 6.02 in 1983 (then a WIB), which is worth 6.456.46. 6.46 was by then way his intermediate time during his 100m PB of 9.86.
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i tend to go with his best split being usually 60  70m & even sometimes 70  80m !
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Strictly speaking, it is the _speed_ at roughly 50/60 meters that would
be interesting, not the overall time. I had a brief look at Mureika's
splits, and I have the impression that Lewis was usually roughly at top
speed in the 5060 meter interval.
(Nevertheless, it is quite possible that he would have been able to
reach a higher takeoff speed, had he not had to bother with speed
endurance and similar.)
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lj'ing doesn't require 100m sprinting excellence
it requires 50  60m sprinting excellence  something which was never as good as his 100m
if he didn't concentrate on running 100s ( especially that last 40m ) but spent his time just on 60m ( running indoor seasons frequently ), he may have got 3 or 4 hundredths quicker over 60m & therefore faster at takeoff  trading off stopping work done for 60m  100m section for extra work in 0  60m  this coud lead directly to improvements in lj
worth remembering that his 60m speed couda been significantly improved  dwight had much faster 60mi pb & therefore possibly faster runup speed
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Re: Carl Lewis 30ft Long Jump
Originally posted by MJROriginally posted by MarlowOriginally posted by MJRIf he had just focused on the LJ, he'd have gone 32 feet, easily.
must have missed that 0 and hit the 2 instead.
I can't believe he would have been any better if he had not sprinted. IMO he would have done worse as a LJer if he had not sprinted.
An interesting speculation is the possibility that sprinting helped saving
him from injuries. In particular, as I understand it, his current
knee/back problems are attributed to the long jump; and with the
stress of additional long jumping, he could conceivably have called it
a day before 1996.
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Re: Carl Lewis 30ft Long Jump
Originally posted by MarlowOriginally posted by MJRIf he had just focused on the LJ, he'd have gone 32 feet, easily.
must have missed that 0 and hit the 2 instead.
I can't believe he would have been any better if he had not sprinted. IMO he would have done worse as a LJer if he had not sprinted.
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