[Music]
magic
[Music]
hey guys it's jason latimer the world
champion of magic and today we're going
to learn about center of mass
and balance and my buddies ralph macho
and billy zabka from karate kid and
cobra kai are on the show to help us
with some home experiments
so that we can show you how to be a
balancing master with objects you can
find around the house
welcome to impossible science
so what is the center of mass
i'm so happy you asked first let's
define mass
mass is the amount of matter or
substance that makes up an object
meaning the center of mass well that's
where an object's mass
is balanced in all directions for
example
take a solid wooden baseball bat now
imagine if we could tie a magic string
onto the center of mass in this bat that
would mean that if we could suspend the
bat from just that point
it will not want to tilt or rotate in
any direction
that means we could leave it in
horizontal position and it would stay
that way
we could leave it in a vertical position
it would stay that way in fact
as long as that string is timed to the
center of mass it would stay perfectly
balanced
in any angle we tilt it or twist that
back
so if you ever wanted to balance an
object well
all we'd have to do is support it
directly above or directly below
the object's center of mass now the
center of mass for a symmetrical
object that's filled with all the same
stuff well that's pretty easy to guess
where it's going to be like the center
of mass for a bowling ball is in the
exact center of the ball
but what about an irregular shape home
experiment time
grab a broom which is an irregular shape
place your fingers on each side
and slowly bring your hands together and
you'll notice
that only one side starts sliding down
and then all of a sudden it starts
teetering back and forth as the broom
helps you find its balancing point
and it's not the center of the object
it's the center of its mass
but we can see the difference here we
can see how the mass has been
distributed
differently but what if we couldn't see
how the mass is distributed
on an object well then we can make that
object balance in an impossible way
and to prove it i've got the kings of
balance on the show from karate kid and
cobra kai i've got ralph macchio
and billy zabka online to show us how to
take normal items
and balance them in impossible ways
thanks for joining me guys
ralph you're going to be going up first
grab a couple of cups all right
and you're going to grab a bill all
right what you're going to do is you're
going to fold it
on its ridge just about a third down oh
just on it's about a third down okay
and then you're gonna fold it up from
the bottom a third
so now you're gonna be looking like this
so
that looks something right all right and
we're going to place it on the cups like
this
all right very well done
great ralph how did you do that the
first time
i'm amazing in this case we know where
the center of mass is when we look at a
bill
we think it's uniform we think
everything like that so i want you to
grab one cup
all right and we're going to slowly pull
it off to the side wait
what okay okay cause i'm gonna do that
and there's there's no
average and it's not yeah that's what's
happening you're no abracadabra
but there is a secret see what happens
is when somebody looks at a bill
we think that everything is uniform we
think that the bill
is the same all the way through and
honestly
because of some of the ink it may not be
perfectly balanced
but when you think of something being
uniform we call
the center of a uniform object you call
that a centroid and most people feel
that the geometric center
of an object has to be the center of
mass all right that's not true
if we add an object this dollar bill
trick costs 1.25
gotcha okay so that so you're tucking
that in there so
yeah so grab the quarter yes all you
have to do
to change the center of mass in front of
your friends is to put a quarter behind
the bill
then when i folded it i folded it into
the bill
right so that's why it happened so now
when you put it up here the center of
mass is actually over here
still being supported so when you pull
that out
look at that ralph you're a magician
magic i no it's impossible
science now you cannot you can actually
take it to your friends
you don't even need cups to do this you
can actually fold it if you're out and
you're
with your friends and you want to do
this you fold it like this place it on
your thumbs
right you can pull one thumb away that's
so cool that's so cool
you got it almost yeah all right now
here's the best part
with the hand that's still touching the
bill grab the belt
turn your hand over let it drop and drop
out and give him the bill
i'm gonna have some homework i love this
that's fantastic
all right now billy in this one we're
gonna use a pencil
and we're gonna find the center of mass
on a pencil take a pencil
all right take a paper clip if you would
or in this case a safety pin and we're
going to place it
in right here now
by adding this safety pin we've actually
changed the center of mass
we've added mass to the object and if i
hold it just from right there
i can get it to balance
like that but wait wait
whoa whoa that's not working get out of
town
okay ah
this is exciting and totally frustrating
at the same time
all right i need i need i need to
understand this principle
there you go there you go like that get
out of here
no way magic that's impossible
okay it's like the crane kick yeah right
it really works it really really works
so why it's amazing that's doing that
and it's still it's kind of moving but
it's still balancing
in this case this really doesn't do much
this doesn't no not even the hole in the
table
is it stuck in okay no but that's a good
question that would
totally work ralph but in this case we
weren't trying to manipulate
the center of mass so rather than just
make this
a pencil i've moved the center of mass
by adding to the base of it i ended up
putting some weight you can build these
at home and i'm going to show everybody
at home how to make these
so you can balance anything but in this
case i've moved the center of mass
below the object right right right
hanging
on that point that's awesome jason but i
didn't even have to add that weight
yeah yeah i'm just making a balance like
that that's an impossible science in
itself
oh hey wait no check it out actually
yeah i had time to i figured that out
well you know i was like what could this
use i thought it needs a washer and a
piece of wire
i thought of that real fast so there it
is anyway
so thanks guys so much for helping us to
find the center of mass to create
balance with our random objects from
around the house
so now that you know this you can go and
use the techniques from the pencil with
your toothbrush or a box and change the
center of mass
to actually balance items around the
house and you can get anything to work
what awesome
a good first pencil card trick and a
dollar bill
amazing that's incredible okay so now we
know that any object will balance as
long as its center of mass
is being supported from directly below
or being suspended from directly above
and if we really want to blow everyone's
minds well we just have to secretly move
the center of mass from where people
think it would be
washers underneath the pencil was a
great idea because the center of mass
is directly below the point of support
underneath the table
and the quarter in the bill while the
quarter was so much heavier than the
bill
that the quarter moved the center of
mass all the way to one side
so look around the house you might be
able to find some empty items that you
can put stuff in to move the center of
mass
and have fun with it
[Music]
let's check it out a quarter
if you like learning about the
impossible let me know by clicking the
like button and subscribing to the
channel and if you have any questions or
topics you want to learn about let me
know about them in the comments below
because you might be wondering about a
question no one's ever asked before and
the right question
well that changes everything have you
ever wanted to break an object with an
invisible force
[Music]
yeah me too welcome to impossible
science
hey guys it's jason latimer the world
champion of magic now what you just saw
was an illusion but it got me thinking
how can we actually break an object with
an invisible force
so today we're going to learn about air
pressure and we're going to do it with
your favorite stars from cobra guy and
karate kid that's right ralph nacho and
billy zapker are coming on the show to
show off our karate chopping skills
to break boards with nothing more than
air okay before we get into breaking
boards i have a great experiment for you
take a piece of paper cut it two inches
by one inch give it a little bit of bend
right there
and i'm gonna place it on the table and
that bend helps it stand
now i'm like three four feet away from
this i can't even touch it
it's probably about four feet i'm gonna
see if i can focus my energy
and knock that piece of paper over i'll
see if i can karate chop this
i'll try it again this time i'll just do
it one hand
not a magic trick it's science what's
actually happening is my last movement
i'm using my right hand it actually
starts at my left shoulder and comes
across the table
so by using my right hand with my left
shoulder by going like this i'm actually
forcing air across the table and that's
what's knocking the piece of paper over
now what you can see
is that air acts like a fluid well it's
got a current
uh it's got a wake as you walk through
it and just like a fluid it has weight
in fact air is heavy even though we
don't notice it the air molecules around
us have weight
and that weight adds up imagine a column
of molecules that are stacked on top of
each other for roughly 300 miles into
the sky
the molecules at the bottom have all the
weight of the molecules above them
pressing down
due to gravity this forces the air
molecules at the surface of the earth to
be tightly packed together resulting in
what we call
high pressure the molecules at the top
of the column
well they have less and less molecules
above them the higher you go
allowing them to be more spread out this
results in what we call
low air pressure down at the surface we
don't notice the air pressure because
air pressure is equal all around us
up down left or right just like a fluid
and we don't feel the air pressure
because the fluids contained by our skin
exert roughly the same pressure
outwards as the atmosphere does pushing
back and they cancel one another out
pretty cool for an invisible force okay
even though you can't see it this
invisible force is there
and today i've got ralph macchio and
billy zabka from karate kid and cobra
kai on the show to show us how to use
our karate chopping skills
to break boards with air thank you so
much for coming on the show guys
thanks for joining jason thanks so today
we're going to be breaking boards
with air pressure and i figured who
better to ask
to help me break boards than you two now
i'm
assuming you guys had a little bit of
experience in breaking boards
yes yeah i'm great with the balsa wood
but you know when you break a board it's
really opposing forces like
your arm is one force and the other side
would be
i guess it's a stand or a person holding
it right
i've mailed you guys a couple of boards
i need you guys to grab a ruler okay
you got one too great it's an elementary
way of breaking boards but the great
part about this is
if you were to put this off the edge of
a table if i were to swing my hand down
and hit this board or this
ruler right now what would happen you
break your hand probably
right now let's change it up a little
bit all right
let's take a piece of newspaper and fold
it into a square
like this all right just one more time
after that
doesn't have to be tight crease just
lightly fold it because we're going to
unfold it in a second but
okay then if you were to place this on
top of here and you're going to hit it
what would happen
they both go flying give it a shot so if
i were
to hit the ruler on the on the edge
and it'll fly up in here even if you
went for it fast it would just launch
everything out and out into space
what we're gonna do is i'm gonna show
you this invisible mystic force
known amongst us science magicians as
air pressure what we can't see is
errors all around us take a newspaper
and unfold it completely
all right and you're going to put the
ruler about four inches off the edge
and give it a little bit of space and
then place the newspaper on top of it
okay so here's the edge here's the
newspaper
now what you can't see is on every
square inch
of this newspaper is a let's say a
square inch of
air and above that square inch of air is
another square inch of air
and that column goes up about 300 miles
and if you were to add all that weight
together
that's where you get air pressure it's
about 14.7 pounds
per square inch so that means that
roughly
23 by 24 inches this square
has about 8 100 pounds of force on it
right now
actually if you do the math on like a a
one square meter table
it's a it's about 10 cars are sitting on
that table
it's it's a crazy amount of force but
there's only one way to really see
its power and that's by creating a
vacuum
when you create a vacuum that's when the
air pushes down on it
now you need to get it as flat as you
can and you don't want it to buckle over
over the top of this ruler it's gonna
because remember it's
it's gonna exert force in all directions
right so if air gets in underneath there
there's gonna be pressure pushing up
so we really want it to be as sealed as
possible
all right so here it is nothing holding
this down but air
when this gets pushed down it's going to
lift up on the paper
right that that momentary suction is
going to create a vacuum
and air pressure will push it back down
and that should be more than enough
to crack that ruler but the real secret
is
if you do it slowly air is going to get
in and if air gets in
it's not going to work you're going to
go over to the edge of your table and
you're gonna karate chop the edge of
this ruler
hard and fast and all the way through
ready
one two three
bingo there we go the crazy thing is
you can see this force against larger
items that this
is this is 3 16 pine wow
all right i'm gonna place it underneath
here again okay this flat here
yeah yeah you don't want the air on the
bottom of this too let's see if i can
get this to work ready
i believe in science so i gotta do this
right blood
very impressive who needs karate when
you can just use a newspaper and break
board
right well guys thank you so much for
joining me on the show and helping me
break boards with air pressure
thanks for the lesson this is awesome
man once you master air pressure you
will have an invisible force
at your fingertips and if you enjoy just
making the impossible possible through
science let me know in the comments
below and as always if you enjoyed the
episode click the like button and
subscribe to the channel
and until next time stay curious because
the right question
changes everything
you're going to take a quarter and
you're going to balance it
on the edge of a bill
this is not a trick it's just a
challenge that anybody can do at home
and you need a bill you can use your 100
ralph
okay and billy you can use the dollar
that you have i got it thanks
so if you if you fold it like this all
right
and you put the coin on the corner of it
like this
even if the center of mass is not on
that side of the bill or this side bill
if it's on this side
the coin is going to tip this way as it
balances out
and the friction is going to allow the
bill to come out this way if the
center mass is on the far bill it's
going to tip the other direction
and slowly pull apart and you'll realize
especially if you hold from the bottom
it gives a little more give in the paper
you can actually get it to balance on
its edge
straight out no trick
ahead and pull it and don't drag it
across the table if you can slightly
lift it off the table as you're doing it
as you pull it tighter oh i see i see
yeah yeah yeah yeah
i think ralph's got it now that nails
can actually lift it up
i'm off the ground ah yeah and throw the
kick
throw the cake wait look at this wait
i'm very proud of myself billy
billy ralph's got it i got it too
it's off the ground that's all done by
finding its own center of mass as you
pull those apart uniformly