# The Flat Earth Society

## Other Discussion Boards => Technology, Science & Alt Science => Topic started by: optimisticcynic on November 02, 2010, 10:24:31 AM

Title: Rope jumping
Post by: optimisticcynic on November 02, 2010, 10:24:31 AM
So my friend is a rock climber and is thinking of going rope jumping. this involves tying a rope to to one side of a bridge, having it hang under the bridge and jumping off the other side. he asked me to come up with an equation that describes the max force experienced by the climber. the rope has a linear stretch force. so it has a nice K value. it has a max stretch of 30%. I was wondering what equations you guys could come up with? I came up with two but I made a lot of assumptions to make a nice solvable system.
Title: Re: Rope jumping
Post by: ClockTower on November 02, 2010, 11:42:24 AM
So my friend is a rock climber and is thinking of going rope jumping. this involves tying a rope to to one side of a bridge, having it hang under the bridge and jumping off the other side. he asked me to come up with an equation that describes the max force experienced by the climber. the rope has a linear stretch force. so it has a nice K value. it has a max stretch of 30%. I was wondering what equations you guys could come up with? I came up with two but I made a lot of assumptions to make a nice solvable system.
Reference: http://www.bungee.com/bzapp/press/pt.html (http://www.bungee.com/bzapp/press/pt.html).
Title: Re: Rope jumping
Post by: optimisticcynic on November 02, 2010, 11:48:55 AM
So my friend is a rock climber and is thinking of going rope jumping. this involves tying a rope to to one side of a bridge, having it hang under the bridge and jumping off the other side. he asked me to come up with an equation that describes the max force experienced by the climber. the rope has a linear stretch force. so it has a nice K value. it has a max stretch of 30%. I was wondering what equations you guys could come up with? I came up with two but I made a lot of assumptions to make a nice solvable system.
Reference: http://www.bungee.com/bzapp/press/pt.html (http://www.bungee.com/bzapp/press/pt.html).
slightly more complicated then that since with bungee jumping  you jump relatively close to the point the bungee is attached to with rope jumping you are fairly far away from that point which adds up to a lot of swing and a lot more complicated system.
thanks though for the response but I do not believe that the to systems would be interchangeable.
Title: Re: Rope jumping
Post by: Trekky0623 on November 02, 2010, 11:52:37 AM
Why would you do this if you value sweet life?
Title: Re: Rope jumping
Post by: ClockTower on November 02, 2010, 12:11:32 PM
So my friend is a rock climber and is thinking of going rope jumping. this involves tying a rope to to one side of a bridge, having it hang under the bridge and jumping off the other side. he asked me to come up with an equation that describes the max force experienced by the climber. the rope has a linear stretch force. so it has a nice K value. it has a max stretch of 30%. I was wondering what equations you guys could come up with? I came up with two but I made a lot of assumptions to make a nice solvable system.
Reference: http://www.bungee.com/bzapp/press/pt.html (http://www.bungee.com/bzapp/press/pt.html).
slightly more complicated then that since with bungee jumping  you jump relatively close to the point the bungee is attached to with rope jumping you are fairly far away from that point which adds up to a lot of swing and a lot more complicated system.
thanks though for the response but I do not believe that the to systems would be interchangeable.
Sorry, but I can't recommend using a regular rope. The chaos of the system could easily cause the equipment to fail at point far above non-chaotic solution. (A twist here and a kink there would mean that link there will snap open.) Bungee resolves the problem with its higher K-values. I'd definitely use dead-weight tests several times, inspecting the equipment between each test, with a raw egg as a stand-in for your brain.
Title: Re: Rope jumping
Post by: Parsifal on November 02, 2010, 12:14:06 PM
Why would you do this if you value sweet life?

Quoting because this is the only possible sane response to this thread.
Title: Re: Rope jumping
Post by: Saddam Hussein on November 02, 2010, 12:26:35 PM
What the fuck?  Like this?

http://gizmodo.com/5164589/rope-jumping-the-latest-russian-suicide-sport
Title: Re: Rope jumping
Post by: Trekky0623 on November 02, 2010, 12:27:23 PM
Why would you do this if you value sweet life?

Quoting because this is the only possible sane response to this thread.

Title: Re: Rope jumping
Post by: optimisticcynic on November 02, 2010, 01:16:37 PM
So my friend is a rock climber and is thinking of going rope jumping. this involves tying a rope to to one side of a bridge, having it hang under the bridge and jumping off the other side. he asked me to come up with an equation that describes the max force experienced by the climber. the rope has a linear stretch force. so it has a nice K value. it has a max stretch of 30%. I was wondering what equations you guys could come up with? I came up with two but I made a lot of assumptions to make a nice solvable system.
Reference: http://www.bungee.com/bzapp/press/pt.html (http://www.bungee.com/bzapp/press/pt.html).
slightly more complicated then that since with bungee jumping  you jump relatively close to the point the bungee is attached to with rope jumping you are fairly far away from that point which adds up to a lot of swing and a lot more complicated system.
thanks though for the response but I do not believe that the to systems would be interchangeable.
Sorry, but I can't recommend using a regular rope. The chaos of the system could easily cause the equipment to fail at point far above non-chaotic solution. (A twist here and a kink there would mean that link there will snap open.) Bungee resolves the problem with its higher K-values. I'd definitely use dead-weight tests several times, inspecting the equipment between each test, with a raw egg as a stand-in for your brain.
we use a rock climbing rope, not a regular rope.
@saddam sort of but we use A. do it one at a time and B. there tends to be a bit more fall before the swing but right idea.