has to be Destin welcome back to smarter
every day it's time for the Puli episode
these are like my favorite things in the
whole world I bought this one it looks
like it goes to a boat or something like
that pulleys are one of these things
that everybody knows about they know
that somehow a pulley will give you a
mechanical advantage but people don't
really understand it we all pretend like
we do but the person that really shows
up and is really clever and they arrange
it in a perfect way and they just make
things work that's like the smart person
that everybody wants to be so the dáil
is smarter every day we're gonna make a
video about pulleys and we're gonna
slowly walk through how they work and
specifically I want to introduce you to
my favorite type of pulley it's called a
snatch block they're really fancy they
can do tricks okay
let's start by picking up these cinder
blocks my kids are gonna show you how to
pick up blocks right if you have to pick
something up you have to pick up all of
the weight of the thing and whether you
know it or not all of the weight of you
how you doing good you can put it back
down how hard was that not that bad the
magic of a pulley is really the magic of
a rope because a rope is always in
tension you can't push a rope if you
pull on this side of the Rope that force
transfers all the way through the pulley
so you basically can redirect a force
that is the primary function of a pulley
redirecting force it's pretty good how
is it the pulley changes the direction
of your body weight so you can use your
own body weight to help you pick
something up very good was that hard not
as hard as what okay so it's easier to
pick it up with the pulley because you
can kind of lean into it right so this
is the part that starts to confuse
people if you can change the way the
pulleys are arranged you can make it
even easier to pick this up do you want
the normal pulley or the snatch block
snatch block there you go go for it so
you split it apart don't cut your finger
off there there you go so this is the
magic of a snatch block we can put a
pulley in any place anytime as long as
it's a rope and a snatch block is big
enough for the rope this is the part
where when you see it happen you're like
oh yeah of course it's easier because of
pulleys but if you don't stop and think
you won't really under
stand what's happening so slowly pull is
it really easy this time a lot easier
okay so this is what's happening the
tension in the rope right here is being
redirected by this pulley because that's
what pulleys do they redirect force but
down here with a snatch block we're
doing the same thing we're redirecting
the force but you have tension in the
rope and tension in the rope so all you
do is you put tension in a rope
somewhere and then you add up as many
ropes as possible on the thing and
that's how you get mechanical advantage
so in this case how much force is on the
cinder blocks do you know two times the
tension I don't know about you but I
understand things a lot better if I can
work with it with my hands so I 3d
printed a bunch of pulleys and snatch
blocks and we're gonna rig these things
up and generate a model of how we were
picking up those cinder blocks when I
pull on this rope that tension transmits
itself all the way through the rope to
the very end wherever the rope is
there's also tension if I pull here
think about the word pulley it pulls on
the rope on the other side of the pulley
right there that pulls on the rope there
at the bottom which then pulls on the
rope on the other side of that pulley
which ultimately pulls against that hook
at the very end all of the ropes are in
tension now if you look down there at
the cinder block you'll notice that
there are two arrows pulling up on that
pulley that's why we get twice the force
on the cinder blocks but what if we want
to pull harder can we just add more
ropes and tension yes we can using this
it's basically a double pulley some
people call this a block and tackle
instead of two ropes pulling down here
we get for just a little bit of force
here even with my pinky finger that's
like 10 pounds of force by just barely
pulling at all this is the same number
of ropes and like pulleys and everything
it's just flattened out so we can see
what's going on so I've got a scale I'm
going to attach a scale to the input of
the rope and remember if we put in put
tension that tension goes all the way
through so as I pull here I have one two
three four ropes connected to the thing
we're pulling so if I put two pounds
here look at that I get eight pounds on
the output
it's awesome I'm getting four times the
force but I'm only moving at 1/4 as far
how far do you think we can go with this
you think we can double it again so now
we have two blocks with four pulleys
each which if you count all those up one
two three four five six seven eight we
have eight ropes in tension on that
block so as I pull here look at this
that's nuts that is a little bit of
force and a lot of output that is some
serious mechanical advantage look at
this though the ropes over close to me
are moving a lot but the ones over near
you aren't moving as much let's break
this thing apart again and see if we can
understand what's happening is so
awesome oh man that's a great shot okay
so here's what we got we've got one
input pulley let's count up the tension
again one two three four five six seven
eight I put two pounds here on the input
that is a lot of force on the output
remember on the block and tackle the
ropes were moving at different rates
we'll think about this on this side over
here that rope is tied up there it's not
going to move on this side I'm pulling
the rope it has to move as much as I
pull it and the same is true for this
one because it's just redirecting that
string but after that everything is
affected by how much this moves so just
playing around with it here you can see
that these ropes move a whole lot more
than that one over there that doesn't
move at all there's a lot going on here
now this is the sort of thing that yes
you can probably explain it with words
but if you have a fundamental
understanding of how this stuff works
and you just know how to use it to your
advantage you can get yourself out of
some really interesting situations for
example the other day the driveshaft
broke on my buddy Jeremy's truck and we
had to figure out how to get his truck
up onto a flatbed trailer without a
winch snatch block we rigged up a pulley
system so that we could pull his entire
truck up onto the trailer using only
ratchet straps we figured it out but
because we were trading force for
distance it was taking forever that's
when a nice guy named Jeff showed up he
drove up offered to help and instantly
understood our pulley system and knew
what to do with this truck we
disconnected one of the ratchets put
Jeff's truck in its place and pull this
truck up until the Rope hit the trailer
one thing I love about Alabama is nice
people like Jeff just stop and help you
and they instantly know what's going on
for exam
watch how quickly Jeff figures out all
the mechanics once I tell them we have
an extra snatch block oh I'm so excited
we're gonna do a double snatch block
goes great I'm gonna put
I'm gonna level with you Jeff that's the
kind of guy I want to be when I grow up
watch how he just picks up a snatch
block and starts working he just knows
what to do
also his hands are just amazing watch
this man work snatch block engaged I
mean that's what you got dude am i
immature I only got two you got a triple
like a block and tackle oh dude that's a
thing of beauty my friend any day you
can use a snatch block is a good day so
yeah snatch box can get you out of a
hairy situation knowing how to use them
can help me make friends and they can
also be a ton of fun zip lines are
basically just snatch blocks you have
the ability to break apart the pulley
and you can insert a cable into it
without having to disconnect the cable
from either in that's essentially the
definition of a snatch block up pulley
where you can insert a line without
having to take apart your line from
whatever it's hooked to snatch blocks
are amazing where else can you get
amazing views of the rainforest canopy
like this without having a snatch block
that's all okay so you can't do a video
about snatch bug so that'll get into
cheap stuff so let's go do that let's
say you got the Jeep stuck you might be
tempted to find the nearest tree pull
the winch out and pull the cable
directly to that tree we think Jeremy
winch the way to go winches the weight
well a snatch block is the way to go if
we pulled that winch cable out directly
to that tree we would only be able to
pull the Jeep with the force that that
winch is able to apply we're gonna
snatch block this bad boy out of here
what you actually want to do is put the
snatch block on the tree side then take
that hook and you hook it back to the
Jeep and so you have twice the pulling
force with your snatch block all right
you got the winch right I gotta win okay
here we go cut the engine off and put it
in gear and just see if it'll pull the
Jeep yes it'll just pull it yeah
well that's scary
it's a lot of force dude
[Applause]
that's good dude that's a lot of force
man thoughts I'm an snatcher blocks are
awesome there's a type of pulley system
we haven't talked about yet it's a
compound pulley system you remember the
block and tackle
we had an eight to one mechanical
advantage well this has the same
mechanical advantage but it does in a
different way you remember we add up the
tension on these ropes and we have one
plus one is equal to two but if we have
two plus two is equal to four and four
plus four is equal to eight we can come
up with an eight to one mechanical
advantage just like that
with less pulleys this is fascinating
and one of the first people come up with
this concept is a guy named Archimedes
to learn more about Archimedes I went to
my local library and got a book by a man
named Plutarch who mentions an
interaction between Archimedes and King
hero of Syracuse it's a really
interesting story but it's going to be
even better if I tell it to you with
this flannel board so it goes like this
Archimedes writes a letter to King hero
of Syracuse he's like yo King hero I'm
really good with pulleys and stuff and
heroes like why don't you prove it our
community is like well I will if you
give me a warship and King heroes like
yo dog here's your worship and then our
committees is like yo dog I hear that
you like pulleys I got pulleys on
pulleys on pulleys and then Archimedes
does something amazing under his own
physical strength
he pulls an entire warship out of the
dock which totally impresses the King
because that's what happens when you
know how to use pulleys you impress
people so people have been using pleased
and snatched logs for thousands of years
and they've been impressed all the way
back in the day with Archimedes but
they're gonna be used for thousands more
that's why you need to know how to use a
snatch block don't take my word for it
though I'll let veteran astronaut
commander Chris Hadfield explain it from
his point of view the biggest difference
between being on earth and being in
space is that you're weightless and when
you're floating around weightless like
on the space shuttle it's really hard to
get leverage you can't dig your feet in
you can't use the weight of things to
hold them in place so having a way to
the hook on one end and hook on the
and apply a steadily increasing force is
really important and that's why on board
the space shuttle we have snatch blocks
they're part of normal equipment in fact
there's a special stowage block for them
that that contains a couple and they can
use pretty regularly both inside the
ship and even outside on a spacewalk
you're in a problem you have a load you
have to pick it up what do you do so
that's what that is exactly what you
want you want to be the person that
knows how to use the snatch block
understands mechanical advantage and get
your team out of the situation snatch
block snatch blocks are amazing I want
to tell you something else that's
amazing and that is the sponsor for this
video which is Kiwi ko Kiwi ko is like
having pure curiosity mailed to your
house to ignite the mind of a child
every month and recently I got to take
my boys to headquarters and we got to
meet the people that designed the kids
the boys gave them feedback on what it
was like to build and play with each one
of these kids in one case my oldest son
collaborated directly with Rebecca who's
a kid designer to troubleshoot something
she was working on in a matter of
seconds she prototyped his proposed
solutions out of toothpicks and string
and they tested it out and it worked
yeah this was a really big moment in his
life it was super fun meeting these
designers and seeing how they come up
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I love this company I'm very proud that
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think that's very evident if you meet
Sandra
the founder and CEO can I am Bush you in
your office ask you some questions yes
let's go where's your office my office
yeah can we go to your desk okay you
don't have an office you're like you're
the boss we have an open office
environment
so why did you start Kiwi coat now
you're you're an engineer yourself right
I am an engineer I grew up making a lot
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making stuff I started to compile
materials and ideas and one of my
friends was like this is so much fun you
just started business around this so so
you created this company in as a like a
fusion between parenting and the desire
to have your kids tinker exactly like I
wanted them to be hands-on I wanted just
them to see themselves as people who
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I hope these kids grow up not only to be
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hopefully all that packaged in a box of
course my pleasure thank you for your
support
oh yeah do you remember how we started
no you don't know how we started I
called the company before you before you
did anything on the internet and I asked
if I could sell your products online
before you had ever worked with any
influencers or anything we so appreciate
that it was really good no I really
really appreciate that do you know what
the promo is yeah you get a free crate
you'd freak right yeah that's what you
get Kiwi co.com / smarter right that's
right and then you have free crate any
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in the case of Eureka create what's best
for you so that's awesome thanks your
time yeah
Thanks thank you I'm Destin you're
getting smarter every day have a good
one bye
there's a road crew on the side of the
road repairing the the guardrail with a
snatch block
[Music]
thanks man have to go on it's kind of
weird I pulled over and said hey could I
check out your snatch blogger like what
are you talking about pretty cool though
to get back in my truck