Falling physics that Every Climber Needs to know

it says kilo newtons

and after this video you will have much

better understanding than probably 99

of the rest of the climbers what these

kilonewtons

actually mean and what forces are

involved in real climbing falls

and then i will explain why big big

whippers

are often much softer than small falls

but first let's find out what is force

i like to play with my instagram

followers so i decided to ask them

what comes to their mind when we hear a

word

force half of the people said that it

has something to do with star wars

fair enough and then before you start

thinking that

half of my instagram followers are

really smart

i have to say that majority of them

didn't vote it at all

so i imagined something like what is

force

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okay but those who wanted to sound smart

said that

force is mass times acceleration which

is the formula that newton

this guy came up with and that's why we

measure

force in newtons which to me is a little

bit funny when you think about it

imagine newton

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so we measure mass in kilograms

and we measure acceleration

in meters per second squared

and we should measure force

in newtons

so to put this formula into perspective

it's like

one newton this guy is pushing

one kilogram of mass and that

makes that mass to accelerate by one

meter per second

every second so here i have a carabiner

and if i put all my weight on it

like so the question is what's the force

right now into this carabiner

so if we look back to the formula we can

say that

mass is my mass multiplied by

acceleration what acceleration i'm

hanging on a tree there is no

movement no acceleration or

is there an acceleration

okay so you've probably seen this

experiment before

i have heavy object and a light object

and the question is if i let go both of

them at the same time

which one is going to hit the ground

first

let's try

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so yes we fell at the same time because

that's what gravity does it makes

objects fall at exactly the same

acceleration of 9.8 meters per second

per second

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so when i'm hanging on this carabiner

gravity is pulling me down

but in order for me to not move down

there must be

opposite force which would be pulling me

up

here i have a spring while the gravity

is pulling the rock down the spring is

pulling the rock

up so the carabiner is actually like a

very very stiff spring

which is pulling me up the molecules of

the carabiner when i'm hanging on it

are being spread apart but they like to

stay together so we kind of

pull back you can't see this expansion

of the quick draw on low forces

but you can on big ones

and so it turns out that this carabiner

has to accelerate

my weight up at the same 9.8 meters per

second

squared which turns out to be about 600

newtons

yep 600 of these need to

hold one skinny guy like me

[ __ ]

okay moving on this quick draw says

that it can hold up to 26 kilonewtons

kilonewton is basically a thousand

newtons

so it means that it could hold about

40 me i wish i would have a clone

machine so i could

demonstrate this to you

and then imagine how many videos all of

this

me could create

[Music]

so if you want to see us create more

videos like this

click the join button it really helps

and i promise i will spend every single

penny i get from you guys

on buying a clone machine

okay so you can hang 40 me

on one single carabiner that's pretty

impressive

although there are things that you must

know first of all

all of these ratings are for new

equipment

wear and tear does not go into that

rating

how bad is that well i asked my friend

ryan from youtube channel how not to

highline because he has a hobby

of breaking stuff and according to his

tests most of the metals tend to last

pretty well

although with soft things things are

totally different black diamond sling

with a

22 kilonewton mbs

what what was the mbs on is 22

kilonewtons yeah

yep a sling rated at 22 kilonewtons

broke at six and here's another one

that's a great condition would not whip

no not whip i would tie my dog to this

though

all right i wouldn't tie a very big dog

to that

hold on let's see how big of a dog could

you have tied

with this oh uh

chihuahua yeah so if you're one of these

people who like to save money

and use very old worn down slings

good luck 24 kilonewtons

that did not stretch that much oh i

guess

guess four kilonewtons

what z [ __ ] man 4

000 newtons okay how much does

such sling can hold well that's pretty

easy just divide 4 000 newtons by

9.8 or if you want easier by 10

and you get 400 kilograms

that sounds quite a lot no 400 kilograms

well all of these conversions from

force to kilograms that i have been

talking so far

are based on the fact that the weight is

hanging statically

once the thing starts falling everything

changes

so what you have just seen is a clip

from dmm

where they dropped 80 kilograms of mass

and that broke a brand new dyneema sling

now my goal is not to scare you it's the

opposite i want to bring the awareness

that climbing gear is

not magic and if you use it incorrectly

it might fail

fun fact do you know this joke that

climbers like to say when they fail on

their climbs

but today is a high gravity day

well turns out that's true gravity does

change from month to month

so if you are one of those people who

like to complain that

today is a bad humidity or bad

temperature now you have a right to

complain that today is a bad gravity day

yay okay let's see what happens when

objects like us climbers start

falling

that was a 10 meters fall

let's see how much force such fall would

generate to the climber

the formula for that would be similar to

what we had before

except that we need to multiply this by

the distance the climber was

falling and divide by the distance the

climber was slowing

down

and did you actually notice how soft the

fall for the climber was

so imagine driving a car in the highway

and pressing on the brake gently

while you come to a stop no problems

right

now imagine you're not driving so fast

you're in a city you're

driving slowly but you slam on a brick

that would not feel very nice right

so here is the first thing i want you to

remember out of this video

the impact to the climber will always be

the product of the distance the climber

was falling

divided by the distance of the slowdown

phase

so let's calculate the falling distance

was about

four quick draws and the slow down

distance

was about two and a half quickdraws and

we get about 860 newtons

or if we would replace her with a

standard 80 kilogram climber

that would be about 1.3

kilonewtons which is not much although

this formula has a little problem

because it will always give you

the value which is slightly lower than

it would be in

real life but showing you how to

calculate more precisely would mean that

most of you would probably just leave

this video right here

but we don't need to do that because we

can rely on real life

experimental data and who is the boss at

providing such data for us

hi i'm ryan jinx and and that's enough

advertisement for you

what we did in this video they put a

device measuring the force on the

climber

and made a series of falls

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that puts me in 1.87

so most of the falls that in my opinion

would be a good delaying example

where below 2 kilonewtons now let's take

a look at these two

extreme examples climber on the left is

5 meters above the bolt

so that would be 10 meters full plus the

slack in the system

the belayer probably has about one meter

of slack

and then there is probably one more

meter of slack

in between the quick draws so in total

we are looking at

12 meters fall while climber on the

right is only one meter above the bolt

and let's say that the belayer is really

afraid and he's going to give a very

hard catch for the climber

so we are looking at 2 meters fall

so a massive 12 meters fall or a small

2 meters fall which one do you think is

gonna be softer for the climber

well let's see we know how much the

climbers will fall but now we need to

find out the

slow down distances for both of the

cases

and that depends mainly on two things

first

is the displacement of the belayer on a

big big whipper

the belayer will probably fly about 2

meters

while on a small fall let's assume very

common mistake for beginners

where the belayer just takes the slack

out and delays very hard

and the second factor is the stretch of

the rope

rope manufacturers claim that if you put

80 kilogram

mass on a dynamic rope statically

like so without movement the rope will

stretch

10 percent and dynamic stretch when you

take elite fall

is up to 30 percent well

up to 30 percent is not very helpful for

us what we need to know

is the stretch of this rope from two to

four kilonewtons force that's where the

lead falls are

and yet again i was texting ryan so i'm

gonna pull

some dynamic rope to see how much it

stretches at first we thought it's gonna

be very easy just go to the park stretch

the rope to different forces

and measure the elongation of the rope

well sometimes easy is

hard when you stretch the rope to

certain force and leave it there

the force will start dropping on the

rope the rope kind of just

gives up while this is very interesting

it's not critical for us

the only thing he needed to do is to

pull the rope as fast as he can to

desired force

and measure the stretch okay

oh my god that's the seven mark

6.9 meters

it stretches when you pull it a dynamic

rope

to four kilonewtons but then there is

another interesting factor

once you load the rope to high forces it

takes

some time for the rope to get back to

its original length

this is what's known as rope resting and

it was really cool to see this in action

see the graveyard getting pulled back

slowly

super interesting probably way more

interesting

to me than it is to you right now so

after he spent like four hours in the

park pulling the ropes

the results were that on forces from two

to four kilonewtons

the rope stretched to about 20 percent

great so let's use that in our

calculations

on a big fall we have 27 meters of rope

in total

so that would be 5.4 meters of stretch

while in a small fall we have 5 meters

of rope

and that would be 1 meter of stretch

however our belayer is panicking and

taking heart

so he will take half of that stretch for

himself

leaving only half a meter of stretch for

the climber

and tadam the big big whipper

will be two and a half times softer for

the climber than a small fall

oh i love fun facts here's another one

imagine that you were climbing

and failed but humidity was good

temperature was good even the gravity

was good that day

you can still blame the moon negligibly

but truly you weigh about a millionth of

your weight

less when the moon is directly above you

so if you want to send

climb when the moon is directly above

you

you're welcome i remember i was

projecting this really long route of

35 meters and the first time i managed

to link all the cruxes and arrive at the

anchor

the moment when i was pulling the rope

up to clip the anchor

my belayer couldn't see me very well so

he just gave me a lot of slack

and on top of that the bolt before the

anchor

was really far really ran out

so while i was dragging the rope up i

lost my balance

and took a fall the wall is flying in

front of me and i'm thinking why i'm

still

falling this is unusual when i stopped

and looked up it was maybe five or six

quick draws above me probably about

15 meters of fall but

the fall was super soft it's like riding

an

elevator so here is another takeaway out

of this video

if the climber is really high up he has

a lot of rope to absorb the fall

so as long as he doesn't fall onto

something

the fall will be soft no matter how you

blade that

however if the climber is not so high he

doesn't have so much rope to absorb the

fall

then soft dynamic bling is really

important and you can ask any light

climber how many times we had their

ankles

broken due to hard catches okay let's

switch gears a little bit let's talk

about

friction because the more friction you

have

the harder the fall for the climber will

be

and here is very extreme example of that

as you can see right here

we z dragged it and so we're gonna have

a lot of friction

when i fall for science

so when you have a lot of friction the

rope close to the climber

stretches normally but the rope closer

to belayer

doesn't stretch that much it's like

having shorter rope and heavier belayer

at the same time

and although the force to the harness

was only two and a half kilonewtons

a lot of the force went pendulum into

the wall

and that's how we break ankles so

extending the quickdraws not only helps

you to clip and avoid situations like

this

but also reduces the impact forces for

the climbers

ok let's circle back to dmm test

breaking the sling the nema slings are

very static they don't stretch

at all and i hope that by now you

understand that this sudden stop can

create a

huge forces if not ask somebody to slap

you

this stop on the face will be basically

what you need to understand so

let's make a very wild and probably very

inaccurate guess

but this sling would stretch to about 5

centimeters so if we drop 80 kilograms

of mass

the distance of 120 centimeters

and the absorption distance is only 5

centimeters

we are looking at 19 kilo newtons

if that is not gonna break the sling

it's definitely gonna break

you whoa if you're still watching that

probably means that you should be

at least a little bit geeky so here is a

dessert for you

there is no gravity yeah

objects don't attract each other there

is

only space time you feel as though

you're being pushed

into the ground not because of a force

called gravity

but because time is moving faster for

your head

than for your feet this and all the

other resources that i use to create

this video

will be in the description and now

please go

send some love to ryan for providing me

with all of his experimental data that i

used in this video

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