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
[Music]
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
[Music]
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
[Music]
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
[Music]
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
[Music]
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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