# Rope jumping

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#### optimisticcynic

• 2200
##### Rope jumping
« 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.
You can't outrun death forever
But you can sure make the old bastard work for it.

#### ClockTower

• 6462
##### Re: Rope jumping
« Reply #1 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.
Keep it serious, Thork. You can troll, but don't be so open. We have standards

#### optimisticcynic

• 2200
##### Re: Rope jumping
« Reply #2 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.
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.
You can't outrun death forever
But you can sure make the old bastard work for it.

#### Trekky0623

• Official Member
• 10061
##### Re: Rope jumping
« Reply #3 on: November 02, 2010, 11:52:37 AM »
Why would you do this if you value sweet life?

#### ClockTower

• 6462
##### Re: Rope jumping
« Reply #4 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.
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.
Keep it serious, Thork. You can troll, but don't be so open. We have standards

#### Parsifal

• Official Member
• 36118
• Bendy Light specialist
##### Re: Rope jumping
« Reply #5 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.
I'm going to side with the white supremacists.

#### Saddam Hussein

• Official Member
• 35369
• Former President of Iraq
##### Re: Rope jumping
« Reply #6 on: November 02, 2010, 12:26:35 PM »

#### Trekky0623

• Official Member
• 10061
##### Re: Rope jumping
« Reply #7 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.

#### optimisticcynic

• 2200
##### Re: Rope jumping
« Reply #8 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.
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.
You can't outrun death forever
But you can sure make the old bastard work for it.