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How much is a kN?
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djnibs


Jul 27, 2006, 8:21 PM
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I'm such a geek


I have no choice but to agree!!! also, you should change your name to Ihategirls!!! burn

lol

unfortunatly, I will also be changin my name to Nerdyboy, so no worries


curtis_g


Jul 27, 2006, 11:00 PM
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I am a little fuzzy on the actual force that would be required to rip ones heart out of ones asshole.

Because you turn all green and angry when you're mad and are suddenly much stonger? :wink:

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Lets assume that 3 times that can rip your heart and all of your internal organs loose and send them flying out your asshole.

Assume that a climber is 175 lbm and F=ma/gc gives us a required force of 6825 lbf to do the deed (13 G's * 175lbm=6825 lbf). So lets assume that the distance required to stop the climber is about 10 ft. (he/she is using a steel cable as a climbing rope with little or no elongation for effect)

6825 sounds reasonable to me, but the assumptions of 10 feet to stop and little to no elongation don't work so well together. Check out this site.

By my calculations 6825lbf ~ 30.8kN (sorry, metric works better for me), and taking into account stretch that works out to ~.73 fall factor for a 80kg (175lb) climber onto steel cable or chain (assume Young's modulus of 784000 just for kicks). 5mm Spectra and a 2.0 fall factor would be only 19.3kN, but since it breaks at 14kN its not so much an issue of your heart coming out your ass as it is your head following it when you hit the ground. :shock:

:D

-a.

you see, you guys all rant rave about me being such a hater...but then we get four (and growing!) pages of this sort of crap that will in end do no one any good and over the course of a week or two settle its way to the bottom of ever other topic that mentions kN along with 4 or five other topics filled with ver confused people trying to flex their junior-year-of-high-school physics muscles arguing about crap that only confuses more people.

I don't care what you think of the English or Metric system...really, I don'o think anyone does.

Nor do I need to be reminded for the BILLION and Oneth time that F=ma



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therefore an carabiner with a strength of 24 kN is capable of holding (on paper) a fall of sufficient force to make your heart exit your asshole.

you, my friend, are brilliant


In reply to:
curtis, are you still there? tell me when and where, i will join you.

well it's nice to know someone else understands my pain

I know I said I would have killed myself by now, but I'm actually get a few friends over to read this post with me and then we're all gunna drink some kool-aid together and go to the meteor of our eleventh god that is passing nearest to earth this next new moon. You guys lauigh but this might be the only train to immortal reign over your own planet and assigned ration of 144 virgins. THATS RIGHT!! IM GETTING A GROSS OF VIRGINS!!!

woah.


jeep4evr


Jul 27, 2006, 11:15 PM
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yup, F=ma, or in a strict physics sense, a=F/m (but lets not get that technical). All thanks to good ol Newton. Just take a first semester general physics course, calculus based. You'll learn all you'll ever want to learn about newtons(which is as easy as kg m/s^2). Then you can impress your friends at the rocks by spewing out the physics of rock climbing while your buddy is up fighting to hold that crimp. Just like I did. Yup.

Don't ya'll just feel smarter after reading my post?


shockabuku


Jul 28, 2006, 8:47 AM
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[quote="curtis_g...and assigned ration of 144 virgins. THATS RIGHT!! IM GETTING A GROSS OF VIRGINS!!!

woah.
I hope you get a better deal than my wife - she got to sex virgins for a while, well over a gross of them. Unfortunatley, they were only fruit flies for a biology experiment - not nearly as exciting as it might read if you wrote it the right way.


jt512


Jul 28, 2006, 8:59 AM
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Oh NO!
A lot of my biners have a Kg marked on them.
I guess I'll have to get a stamp, and change the g to an n. :lol: :D

Cosmiccragsman

Yep, kg is also a legitimate unit of force, too. But if your biners are old enough to be marked in kgs...

Strictly speaking, that is not true. The kg is a measure of mass.

Actually, engineers (being the lazy fcukers that we are) created the basterdized kg-f unit --- because dividing by ~10 is too much work. Thats my favorite metric unit.

Strictly speaking, it is true. kg is a measure of mass in the SI, but the SI is just one arbitrary set of definitions. Given an acceleration, force is just mass times a constant. Therefore, units of mass and force contain exactly the same information, and can be used interchangeably -- essentially what ihategrigris is saying.

Jay


devils_advocate


Jul 28, 2006, 9:03 AM
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I hope you get a better deal than my wife - she got to sex virgins for a while, well over a gross of them. Unfortunatley, they were only fruit flies for a biology experiment - not nearly as exciting as it might read if you wrote it the right way.

That post went from highly intriguing to I couldn't give a damn far too quickly.


devils_advocate


Jul 28, 2006, 9:09 AM
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Strictly speaking, it is true. kg is a measure of mass in the SI, but the SI is just one arbitrary set of definitions. Given an acceleration, force is just mass times a constant. Therefore, units of mass and force contain exactly the same information, and can be used interchangeably

But acceleration isn't always a constant, hence the need for an independent variable.

::stoking the fire emoticon::



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Actually, engineers (being the lazy fcukers that we are)...

I resent that, I'm not lazy. I... oh wait, I'm here surfing rc.com... I guess that does qualify for lazy. Carry on.


jt512


Jul 28, 2006, 9:42 AM
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Strictly speaking, it is true. kg is a measure of mass in the SI, but the SI is just one arbitrary set of definitions. Given an acceleration, force is just mass times a constant. Therefore, units of mass and force contain exactly the same information, and can be used interchangeably

But acceleration isn't always a constant, hence the need for an independent variable.

Acceleration doesn't have to be constant to measure force in kg. You simply define 1 kg of force to be equivalent to the amount of force on a mass of 1 kg at an arbitrary value of acceleration, such as g. You can analogously define units of acceleration as units of force by referencing them to a standard mass, which is why airplane pilots can sensibly talk about experiencing "2g's of force" in a tight turn.

Jay


curtis_g


Jul 28, 2006, 10:12 AM
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ok, so read all of page 4. now read it again... now does anyone understand my motives behind my first reply way back on page 1?

it's like im psychic or something :roll: :roll:


catbird_seat


Jul 28, 2006, 10:56 AM
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On most of my carabiners there is a kN rating of 25 to 31 for closed gate. But how much is that? How much weight could that actually hold, say falling from 40 feet? I just want something more concrete in my mind about how strong my carabiners actually are.

Here's a monkey-wrench-in-the-works for you: if you want to know how strong your carabiners really are, it is not the closed-gate strength that matters, but rather the open-gate strength. That is because biners often pop open the moment they are weighted in a fall. Thus, you should be asking yourself how big a fall can a 7- or 10-kN-rated biner hold, and is the difference between 7 and 10 kN important?

Jay
This is a misleading statement and since this is a beginners forum, I'll correct it. The gates do not "often" open in a fall. "Occasionally" is much more accurate. It's rare. Solid gates can "flutter" if the rope is whipping through at a fast rate. This doesn't happen with wire gate carabiners.


jt512


Jul 28, 2006, 11:40 AM
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On most of my carabiners there is a kN rating of 25 to 31 for closed gate. But how much is that? How much weight could that actually hold, say falling from 40 feet? I just want something more concrete in my mind about how strong my carabiners actually are.

Here's a monkey-wrench-in-the-works for you: if you want to know how strong your carabiners really are, it is not the closed-gate strength that matters, but rather the open-gate strength. That is because biners often pop open the moment they are weighted in a fall. Thus, you should be asking yourself how big a fall can a 7- or 10-kN-rated biner hold, and is the difference between 7 and 10 kN important?

Jay
This is a misleading statement and since this is a beginners forum, I'll correct it. The gates do not "often" open in a fall. "Occasionally" is much more accurate. It's rare. Solid gates can "flutter" if the rope is whipping through at a fast rate. This doesn't happen with wire gate carabiners.

How do you know they don't open often? I think, rather, you assume they don't. I suspect that they open a lot more often than most climbers realize. Gates can open in a fall by at least four mechanisms: flutter, whiplash, direct contact with the rock, and contact with the bolt head. Flutter occurs by vibration; and whiplash, by inertia. Both wire and conventional gates are subject to both phenomena, though wiregates less so. Direct contact with rock features or the bolt head should be self-explanatory, and wire gates are more prone to this than conventional gates (which is why I hate wire gates on the bolt end of draws). Since this is the beginner's forum, let's let the newbies, who might be in the market for their first set of draws, know right away why it's worth investing a few more dollars per biner to purchase 10 kN of open gate strength instead of just 7 or 8.

Jay


Partner wideguy


Jul 28, 2006, 12:31 PM
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Since this is the beginner's forum, let's let the newbies, who might be in the market for their first set of draws, know right away why it's worth investing a few more dollars per biner to purchase 10 kN of open gate strength instead of just 7 or 8.

Jay

Crap!! So my draws with Dynotrons/Hotwires , both only rated at 9kN, are fatal?!?!?

great... Anyone want 12 draws with the above biners and 24' dyneema 10MM slings? :wink:

They are, as far as I know, all free of micro fractures.


devils_advocate


Jul 28, 2006, 12:49 PM
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They are, as far as I know, all free of micro fractures.

Yeah, right... nice try wideguy. No doubt there is cat piss on those death draws.


greenketch


Jul 28, 2006, 12:54 PM
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great... Anyone want 12 draws with the above biners and 24' dyneema 10MM slings? :wink:


I don't know if the biners are exactly fatal but a draw that has a 24 foot dyneema sling would be pretty rough. :) :wink:


coach_kyle


Jul 28, 2006, 12:57 PM
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Before you climb again, go back to high school and take the first semester Introductory Physics. In nearly all schools, this is a class on basic mechanics. Climbing will be extremely dangerous for you until you do.


bill413


Jul 28, 2006, 1:35 PM
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great... Anyone want 12 draws with the above biners and 24' dyneema 10MM slings? :wink:


I don't know if the biners are exactly fatal but a draw that has a 24 foot dyneema sling would be pretty rough. :) :wink:
Aren't those to clip the anchors before even leaving the ground?

Don't know why I'd want 12 of them, though.


devils_advocate


Jul 28, 2006, 1:42 PM
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Before you climb again, go back to high school and take the first semester Introductory Physics. In nearly all schools, this is a class on basic mechanics. Climbing will be extremely dangerous for you until you do.

As an engineer I apply my knowledge of physics and science to most situations, including climbing, simply because that’s how I think and it entertains me to do so. Anyone who knows engineers know that we too often analyze (and over-analyze) things mathematically. Simply put, we’re dorks. I think the modern engineer has broken away from the traditional nerd stereotype, and can be just as “cool” as anyone else; but there will always be that underlying affinity for numbers and analysis, and therefore we will always be dorks. I submit this thread as evidence A.

I always encourage learning of physics. I think it is a great field, applicable to many aspects of life, and I find it interesting. That said, I do not agree with your statement that failure to learn physics will make climbing extremely dangerous. A person can learn to be an safe climber without any knowledge of Newtonian mechanics, mathematics, or the first law of thermodynamics. I don’t think it hurts to know these things (although it can hurt others. E.g. curtis_g, who no doubt is in some sort of anaphylactic shock right now) but it certainly isn’t a prerequisite.


shockabuku


Jul 28, 2006, 1:46 PM
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Strictly speaking, it is true. kg is a measure of mass in the SI, but the SI is just one arbitrary set of definitions. Given an acceleration, force is just mass times a constant. Therefore, units of mass and force contain exactly the same information, and can be used interchangeably

But acceleration isn't always a constant, hence the need for an independent variable.

Acceleration doesn't have to be constant to measure force in kg. You simply define 1 kg of force to be equivalent to the amount of force on a mass of 1 kg at an arbitrary value of acceleration, such as g. You can analogously define units of acceleration as units of force by referencing them to a standard mass, which is why airplane pilots can sensibly talk about experiencing "2g's of force" in a tight turn.

Jay

Ack! Pilots (at least the ones I work with - fixed wing and rotary) are boneheads. Anyway, are you saying that fall factor is somehow related to impact force? I wonder if you're the only climber alive who knows this? :P


shockabuku


Jul 28, 2006, 1:49 PM
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Before you climb again, go back to high school and take the first semester Introductory Physics. In nearly all schools, this is a class on basic mechanics. Climbing will be extremely dangerous for you until you do.

As an engineer I apply my knowledge of physics and science to most situations, including climbing, simply because that’s how I think and it entertains me to do so. Anyone who knows engineers know that we too often analyze (and over-analyze) things mathematically. Simply put, we’re dorks. I think the modern engineer has broken away from the traditional nerd stereotype, and can be just as “cool” as anyone else; but there will always be that underlying affinity for numbers and analysis, and therefore we will always be dorks. I submit this thread as evidence A.

I always encourage learning of physics. I think it is a great field, applicable to many aspects of life, and I find it interesting. That said, I do not agree with your statement that failure to learn physics will make climbing extremely dangerous. A person can learn to be an safe climber without any knowledge of Newtonian mechanics, mathematics, or the first law of thermodynamics. I don’t think it hurts to know these things (although it can hurt others. E.g. curtis_g, who no doubt is in some sort of anaphylactic shock right now) but it certainly isn’t a prerequisite.

I'm not an engineer - but I submit that everyone knows something about Newtonian mechanics and thermodynamics even if they can't use numbers to describe it quantitatively. My family calls me a nerd - I'm a physicist.


Partner wideguy


Jul 28, 2006, 2:31 PM
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great... Anyone want 12 draws with the above biners and 24' dyneema 10MM slings? :wink:


I don't know if the biners are exactly fatal but a draw that has a 24 foot dyneema sling would be pretty rough. :) :wink:


LOL!!!! Ya know, I'd go back and fix that, but it's funnier to leave it.

and OF COURSE they have cat piss on them, if it works to mark your rope should be GREAT for slings. Noone's stolen then yet.


cosmiccragsman


Jul 28, 2006, 5:49 PM
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Hey Curtis;
If you were going to kill yourself at the end of 2 pages, I'm curious at what you will do at almost 6 pages. :lol: :lol: :lol: :lol:
I was looking forward to your wake, so I could drink a lot of Newcastles,
and give toasts in your name. :D

BAH, young wankers, always trying to change things. They should have kept the Kgs rather than change them to Kns. :?

Cosmiccragsman


sick_climba


Jul 28, 2006, 10:03 PM
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Hey Curtis;
If you were going to kill yourself at the end of 2 pages, I'm curious at what you will do at almost 6 pages. :lol: :lol: :lol: :lol:
I was looking forward to your wake, so I could drink a lot of Newcastles,
and give toasts in your name. :D

BAH, young wankers, always trying to change things. They should have kept the Kgs rather than change them to Kns. :?

Cosmiccragsman
In reply to:
curtis_g wrote:
you are INSTANTLY my worst enemy.

I hate you and I don't think I will ever find it in my heart to forgive you.

If this reaches 2 pages I might commit suicide.

about 225 pounds

Please search other threads.

And please, everyone else, don't keep this on the front page by responding.

peace

crtis

Curtis_g died today on 7-27-06, he commited suicided after the thred titled " how much is a kn" reached three pages. we remember curtis best ranting about random things on rc.com and But he is surely now being lazy in heavan or more likely climbing some awesome formations in hell!

dude this was on page three!


cosmiccragsman


Jul 28, 2006, 10:20 PM
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Hey Sick_climba;
On page 5, July 28, He had Risen from the Dead. :D
Lord only knows what he'll do on the 7th day.
Maybe start the Tribulation? :twisted:

Cosmiccragsman


sick_climba


Jul 28, 2006, 10:50 PM
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I know the fucker pmed me about my gri gri... its like dude... get off the celieng and relize you are dead, it only works for jesus... I mean gawd what is the world coming to?


cosmiccragsman


Jul 28, 2006, 10:55 PM
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^^^^^^^^
lolololol
:lol: :lol: :lol:

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