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Why Snatch Blocks are AWESOME (How Pulleys Work) - Smarter Every Day 228
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- Hey, it's me, Destin.
Welcome back to Smarter Every Day.
It's time for the pulley 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 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 the perfect way
and they just make things work,
that's like the smart person that everybody wants to be.
So today, on Smarter Every Day,
we're gonna make a video about pulleys,
and we're gonna slowly walk through how they work.
And specifically, I wanna introduce you
to my favorite type of pulley, it's called the 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? - 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 the force.
That is the primary function of a pulley, redirecting force.
(child grunts) That's pretty good,
how was it?
- Hard.
- 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. - Not as hard.
- Not as hard as what? - Just picking it up.
- Okay, so it's easier to pick it up with the pulley
because you can kind of lean into it, right?
- Yes sir. - Right.
- So this is the part that starts to confuse people.
If you can change the way the pulley are arranged,
you can make it even easier to pick this up.
Do you want the normal pulley, or the snatch block?
- The snatch block. - Snatch block!
There you go. (pulley clacking)
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 at any time
as long as there's a rope, and the 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 understand what's happening.
So slowly pull, is it really easy this time?
- It's a lot more easy. - A lot easier, okay.
So, this is what's happening:
the tension in the rope right here
is being redirected by this pulley
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