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   Jumping ropes
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Grimbal
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Jumping ropes  
« on: Oct 21st, 2011, 3:00am »
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Just a silly question that crossed my mind.
 
If we had 4 arms, could we use two jumping ropes at the same time?
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towr
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Re: Jumping ropes  
« Reply #1 on: Oct 21st, 2011, 8:54am »
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Let's tie two people together and find out.  Tongue
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Re: Jumping ropes  
« Reply #2 on: Oct 21st, 2011, 2:20pm »
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I'm reasonably sure you can't.
 
You definitely can't with both ropes going in the same direction around you - if you change your reference frame so that the ropes are stationary and your body rotates, it's pretty obvious that your arms (or the ropes) get twisted around each other.
 
What I can't visualise well enough to rule out entirely is having the two ropes go in opposite directions, egg-beater style, though I suspect they also get tangled...
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Grimbal
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Re: Jumping ropes  
« Reply #3 on: Oct 23rd, 2011, 3:04pm »
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Well, there are a two ways to hold the ropes.  If you name the arms as A, B, C, D as a geometer would, i.e. respectively back right, front right, front left, back left, you can hold the ropes A-D and B-C, or A-C and B-D.  
 
A third way would be A-B and C-D, and you would turn the ropes laterally.
 
Then you can turn in the same direction or in opposite directions.
 
I believe all of these ways are possible.  At least topologically.
« Last Edit: Oct 23rd, 2011, 3:05pm by Grimbal » IP Logged
Hippo
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Re: Jumping ropes  
« Reply #4 on: Oct 24th, 2011, 8:23am »
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Just an easy answer ... take two ropes to each of your 2 hands simultaneously and try. There will be no problem with it. So if you have 4 arms, you could bind pairs of them together to get the same solution.
 
OK Grimbal thinks about more complicated patterns, but that was not asked Wink.
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Re: Jumping ropes  
« Reply #5 on: Oct 24th, 2011, 10:01am »
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I didn't even define what "using a jumping rope" means.  That leaves many options.  Roll Eyes
 
My idea was that the 4 arms point at 4 directions at right angles.  Maybe I should call the arms N, S, E, W.
 
In the N-S and E-W case (i.e. crossing ropes) you start with both ropes down, N-S above E-W.
E-W is "outside", it can move unhindered S and then up to the horizontal.  N-S can then move E and up to the horizontal, touching E-W from below.
E-W is above, it can continue to overhead.  N-S follows closely and passes over E-W.  We end up with E-W and N-S crossing over the head, N-S over E-W.
 
From there, both ropes can go down the front just the same way.  N-S is outside, it can go down unhindered, E-W can follow.
 
Now I need someone who is ready to try it out with me, back to back.
« Last Edit: Oct 24th, 2011, 10:02am by Grimbal » IP Logged
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Re: Jumping ropes  
« Reply #6 on: Oct 25th, 2011, 8:07am »
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Okay, yes, using a pair of ropes as though it's a single rope works - the ropes twist at the ends, but the twists meet and cancel in the middle (just like with a single rope with fixed handles)
 
What gets tangled is having the two ropes far enough out of phase...
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Re: Jumping ropes  
« Reply #7 on: Nov 19th, 2011, 7:48am »
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let assume if we tie the two ropes and this is one then this is possible. if the one rope in first two hands and the other rope in the next two hands then this is not possible as we are having the same two legs.
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Re: Jumping ropes  
« Reply #8 on: Dec 9th, 2011, 7:10pm »
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Then the option begs to be identified. What if we had two forearms?
 
I had to say it.
 
Sorry
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Re: Jumping ropes  
« Reply #9 on: Jun 28th, 2012, 3:51am »
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Two persons stood opposite each other and extended the rubber band.
One player jumped and stood on one side of the rubber band, carrying the two sides together
 
 
 
 
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Re: Jumping ropes  
« Reply #10 on: Jul 17th, 2012, 4:33am »
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James I think you're right, can we confirm?
 
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Re: Jumping ropes  
« Reply #11 on: Jul 18th, 2012, 5:28pm »
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I think you could!!!
don't get me wrong you would have great difficulty trying and would probably fall and smack yourself in the face alot... but you definetly could with alot of practice and determination, it would help if you were double jointed in all 4 of your arms.
 
Thats the benifit of being a superior race we can train ourselfs to do anything if we try hard enough!
 
Good debate !!!! Shocked
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