today
we're going to change
topics
going to talk to you about
fluids
hydrostatic pressure
barometric pressure
if bernal we
forget gravity
and i would have a
compartment
closed off
and filled with a fluids could be to the
gas or it could be
electric
because every eight-year
and i'll apply a forceful means
that direction
and i apply pressure
pressure is defined
of course the quieted by area
has unit newton's first grammy dir
which is also call
off-guard
one with inputs from either as one
possible
in the actions of gravity
the pressure
this everywhere
induced vessel
and that is what school
off calls principle
boss calls principal source but the
pressure applied to an end close through
it
is transmitted to fundamentalist
to every point in different
and to the walls
off the container
keep in mind pressure is a skater
it has no direction
has a direction
and the force excited by the fluids
or anything therefore also on the wall
must be a everywhere perpendicular to
the wall
because if there were any kind gentle
component
then the fluid would start to move
action equals minded reaction so it
starts to move
and we're talking here about ascetic
fluid
so if i take any
element i think one here at the surface
little element belt tightening
and the force must be
perpendicular to that surfaced
belfast
and so delta f
provided by delta ii
inanimate incase
for delta equals to zero
is then that pressure p
has some forty amazing
consequences which i by no means
so intuitive
this is the idea of a hydraulic
i have here
vessel which has every
julia shape
opening here
and let there be here
pittsburgh on it
nearly a month
and year
with every eighteen
it's filled with liquid
everywhere
and i apply here force
f_-one
before saxton
sort of pressure that i apply here
is at one
whatever you want to political we were
in the fluid
that pressure must be the same
for now
are just assume that the effect of
gravity which idle discussion with lee
doesn't change
the situation
for significantly
but i will address the gravity very
shortly
sort of pressure then will be the same
everywhere
depression due to their site is excluded
by the by april
and sorted through must be the same
it's really quick is not moving
so what that means if it is a tool
over a bomb
were one hundred
it would means that this force
put behind the times less than that one
in other words i could put a here awaits
amassed ten kilograms
and yet i cooked food
thousand kilograms
and it will be completing an equilibrium
that's not so intuitive
this is your receipt
all the russians
what they do is they put a couple of
days
by blow that up here
so these are the specs for it
there is a wrong here
and on top of it is a car
someone pushes here
and then
this goes up
cargoes
if i push here
widow force a little bit more than ten
kilograms so that would be on the
blueprints
this level will go up
and so your first thought maybe g isn't
that a violation of the conservation of
energy
isn't it i'm kind of dead getting
something for nothing
well not really
suppose i push this down over distance v
one
then the amount of through with that i
displaces the volume
is a long time to do you want
that's wrong with ends up here
so this one will go up
over this wednesday too
with the same amount of through with
that
leaves here
adds there
another words
it won't be long
must be a true
finds the tube
if the force here
sometimes
left and the force bear
the work
that i a m doing
on the left side
f_-one
fund v one
it before it hits from the times less
than that
dished instead i mean
it on the time
larger than the two
because a to over a one is a hundred
and so f one b wong
will be the same
as etc to detour
on the times
mobile force
over on the times larger this
and sort of product is the same so what
did i do when i post is down i get back
in terms of gravitational potential
energy
by lifting the car
so if i wanted to move the car up by one
leader
and that the ratios from the plum i
would have to move it down by a company
that's a little bit on practical so the
hydraulic presses are designed in such a
way if you can just check it like that
in every time that you bring it up
that liquid flows back in again
into this
cycle the hydraulic jack
but indeed you have to go effectively
hundred meters than
what it costs go up
by while neither if
the ratio is filled with one
no gravity of course has in effect
on the pressure in the fluids
if you go down into the oceans
we know that the pressure we'll go up
and that is the result
of gravity
and i would like to derive
pressure increase
let this be
the direction of increasing y
and i'd shows a week
they quit elements will get his end of
the quick itself
i contribute in any shape that i want to
let this taken nice horizontal slab
and it is a really so the bottom is also
a
and let this be a kite
white was built the light
and it is a type y
and the pressure here
you what without the white
and the pressure here
you alright
and dissolved act has amassed delta m
and equipped
president of the role which could be a
functional why we'll leave it open for
now
and so
this maths last that i have here is the
volume
bunkered entity
and the volume is eighty
every year
i don't know why
and then times identity which may be
functional y
led by quoting
all the forces at work here
there's gravity
which is dealt i m
packaging
give direction
on up
the force of ports
due to pressure all the
how it that's what we want to evaluate
it's always perpendicular
the services
we talked about that earlier
for decided comes in like this
europe something like this to force
from the bundy something like this
and from the top
i called it
only
consider
the vertical direction because all
forces in the horizontal plane
we'll cancel
for obvious reasons
so now that has to be equilibrium
destroyed elements is not going anywhere
just standing still win the fluid
and so i don't have that f_-one
which is in this direction
my days after we
miners delta m
g
with europe
only then is the fluid element
ecstatic equilibrium
but everyone
is this pressure times the area
border dispute
level why kind of the area
i'd have to
exp
at level what was dealt a wife
time period
minus
delta n is a delta lifetimes role
so i got my understanding
aren't delta y
which could be a function
role could be functional white g and
that people zero
nor did i lose my area
i'm going to rearrange this slightly and
divide by delta y
so i get that him
at the level what was delta y
might have to pressure
level why divided by delta y
equals
switch that around so i bring this to
the other side
equals minus
role
g
and it i think the limit in case of this
for delta y ghost zero
then reva police
the pty
and installed you
when you go to increasing values of why
but the pressure to go down minus line
very natural if you go decreasing values
of life
and the pressure
we'll go up and we call this
hydrostatic pressure
i go
at it
pressure
soldier the fact that there is greta van
without gravity there is no
hypothetically
now most fluids most liquids
practically incompressible
in other words the deputy optic
cannot really change
and so therefore
you could to remove this
and simply always use the same bend
extremely difficult to take
relentless forces
and precious to change a density
over the quit
that at the gas gases compressible
you can very easily change
the density gas
toward equates
incompressible
if i have here
the pistons and i have here
well-equipped
and i put a force on here
would be impossible for me
make that
volume smaller even
by the fraction of a percent
that would be impossible if this however
were guests
that would be very easy
for me to push that in
and two
change the polemic the small born in
small and thereby
make the density of the gas go up
if i took a slash hammer
and i would hit
a plastic yellow
just bring and petals fulfilled his air
x like a caution
i could squeeze it
if i get to slash hammer home the marble
floor
i could not resist
and the force
on the marble program on the hammer
would be way higher
cause i don't have this
push in action
if i can take
faith can
and we have one here
we have to
and baseband code expelled tuticorin
with water
and let along
is filled with hair
and ahead with this last summer
and that's why i could push it
this one however
doesn't want the volume to be decreased
sort of course
like on the marble floor will be wayne
dyer
but remember
at sports provided by area its pressure
and according to pasquale
that pressure
propagates undiminished in the whole
foods
and so if i would
shoulder boards through here
by getting huge force
extremely small area of the bullets
sort of pressure inside the decree
will go up enormously
and dick and might explode
provided that'd really feel free to
bring with water because
if there is a let
then you have this caution action
well i don't remember whether there's
every year or whether there's air in
there
i lead you to decide
so will fire aboard it from the site
and then we'll see which can
explodes
and which does not
and the one that doesn't is the one that
has ever in it
and the woman explodes
at the watergate provided that we really
filled it with a grim
feel something in there
exxon woman okay
all right
nichols bullets
okay ridiculous
would you tell me which can is filled
with their own which can still please
through one zero
to me
it's wonderful
has a nice hole here and i thought there
and this one has a whole year edible
thereabouts
thoughtful kamal so we don't want
had water in it and by the way still
there
these things are not so
intuitive
i will assume from now on
liquids
i completely incompressible
another words i can now use
this law that we have there
and do a very simple integration
i have now the people
so i can integrate
compelling he wanted to kill
why
level ito
level like to
level why won't
pressure p one
in the liquid
and that he called no miners road g
you why
integrated
and why won't
like to that's not really windy role
because we always constant what was not
a functional
with the atmosphere of europe
that's more difficult because roe is a
function of altitude with the atmosphere
with liquid
until we get that be too
minus you want
equals miners role gene
i'd like to
minus why bother with the school off
caldwell
i'd prefer
to ride it slightly differently
but it's the same thing i'd like past
nine years so i switched it around
i'd like to
mine might want to what it means is i
see immediately that the flight to
minors to buy one
positive with higher than this
but the pressure people is larger than
the precious to what they are
completely
identical so this is the hydrostatic
pressure
discussed quite bizarre consequences
suppose i had a
address so that i feel rhythmically
had a lot of change shape
like so
rather strange
robert phillips
liquids at this level
and
the level here
white too
and i think the bottom of this battle
and call his wife want
excellent idea we have precious do you
want
and right there
the oppression he too
well what's pasquale is saying now is
that the
pressure here
everywhere the same
because white two-minus by one
is the same for all these points here
and so you will say well this photo link
to woody
arguable say welk
if i take here
column
nicely through nickel vertical column
which has a reiki
and i call this separation
h for simplicity
then the white or beth call them
that's the way told the liquid
would be a really
fund eight steps napoleon
fund prevented the albany creek role
heidi
and so he would say that's of course
the weight
the bottom you have to carry that weight
and sort of pressure at the bottom is
dead weight divided by the area
so that it'll
h_g_
so you would say that's very clear
yeah maybe
but how about here
the pressure is the same
couldn't be any different if the
pressure were different here
the ticket would start to flow
but you know you don't have that call in
case you over you
yoni have it here
and how about here
the consequences
of boss calls lawyers
that if you have a vessel like this
how you feel that all the way it was a
recruiter
at the pressure here at the bottom
will be exactly the same
this vessel
which is filled with liquid all the way
through the bottom and yet the weight of
the things way more
then the way to base
yet one of the post cold war
pressure differential is the same
it had nothing to with you
relive at the bottom
open ocean open-air
butyrate
if they are
when would go up in uae
and we also expect
that the pressure
real go down
doesn't go down
linearly
like liquids
that responding to your because well
doesn't change in the case of air
density
dust james's altitude
but if i can take
crest anyway
toronto although it will be probably
happens here
just like i did hear
in the liquid
i think i want to press and indeed i
could have taken a really
and i will you all these air
then i would get the right answer
for the pressure here
because i do that bear
at work attitude work here
and what i find them
but i find that at the bottom
at sea level
i find roughly
one kilogram force which is pendleton
prescription
it means then
that this whole column it might take a
one square centimeter
probing all the way to the top of the
atmosphere if you are looked a lot of
this
that that would wait
one paragraph only
all that area
one kilogram per square centimeter
if you convert that looking to prescribe
either
you get roughly
and food if it's possible
and that is cool generally
one atmosphere
it's called the atmospheric pressure
saudi air
bushes dot almost that this is the
atmospheric pressure not unlike the way
that they quit
which is down
because of its weight
and increased pressure as you go down
is atmospheric pressure
it's also often pull
barometric pressure
ideal of a barometer
you have my hand i might have has an
area of roughly on the fifteen square
centimeters
forces always perpendicular to the
surface
i discussed it several times
request i mean either attitude prevalent
rate of one kilogram div div two
the air about me
that means hundred fifty kilograms
pushing down on my head
bite my head not going down
well the brothers also on the fifteen
univer
so
i_q_ very comparable i don't even notice
it
that there is a huge force
the direction and huge force
in that direction
so how can i measure
these atmospheric pressure if i can
steal it
the way that you can measure it
espy
the following experiments
your take
he put a hose in the victory
battle to a very shortly
december joe's visit battles
are we going to emerged almost
completely into that liquid
but it's completely filled
reason liquid
and then we left it out
as we left it out
we will see
that the liquid will stay there
their reputation
pushing him
and i put out and put out and put out
and put it out
and a comes a time
it will not stay in there anymore
goes way down there now vessel
it left off
visit now aunty
you're a democrat
they're going to wait
that we can measure the barometric
pressure and i will show you shortly how
that works with the first
convince you
that if i
that all this
cranberry juice inside the
proving that i have
i put my finger on top of the tubing
analyst without
note is that the cranberry juice things
there
not running down
only when i take my finger off the top
and it goes down
as long as i hope my finger on the floor
going down
if mike
homes were long enough and we will know
shortly hollow
went out to be more than ten meters
then we would see the cranberry break
loose from the pool
this is a way that you can measure
the atmospheric pressure
and i will now be
more qualitative about that
i believe that the christian because i
like that equation
alleging that we have
these experiments
which in the old days more than don
requested poses which was done with
glass tubes
and suppose i end up
theories liquids
here is such a
and that
liquid had broken toys and fear
and beer
liquid
this is why i want
it is quite cool
is his depression he won't
and writing five-year
is the pressure people too
which is zero utenti nothing
little bit of
vapor pressure but that's very small
and so this distance here
but at the age
and so now what is the
pressure here people
which of course is the barometric
pressure
it just ex post forget this for you
lp one
litespeed kill
equals row of the liquid
hygiene
times by two minute by one which is h
but they do is zero
soapy rom
equals row
ph
and that is the barometric pressure so
all i have to do is take a liquid
known advantage ill be bequeathed
measure how far i have to pull that
holds up before
the liquid rate rose
and then i know what the barometric
pressure
of this was done in the early days in
the
seventeenth-century
by torricelli use
mercury
and he found that
mercury by the way
azad entity fifteen point six
time spent in it
kilograms per cubic meter
provision mercury
he found that age
is about seventy six centimeters
or point seven sixty eight
just a fact changes it will be from day
to day
particularly if you centimeters
little dollar little up
it up barometric pressure at higher
and when it down
and soda barometric pressure p one
isbn thirteen point six
but clinton period
bungee for which i will take ten
and the heights is all for nt seven six
and at one point all three
i'm spent to defeat
off-topic
which company close to the one kilogram
force
prescription admitted that i mentioned
to you earlier
what was fierce pressure is defined in a
very special way in a very precise way
that it is exactly
the pressure
when the call in here
is seven hundred
and sixty millimeter is of mercury
then we call the pressure here that's
the definition
one atmosphere
but you can notice and experiment with
water
wesley as we try to do with race
cranberry juice
the dented the water is thirteen point
six times lower than that of mercury
sort of pollen has to be thirteen point
six by mta
higher than seventeen six centimeters
which is about the meetings
so you would have to raise the think up
to ten meters
before you would see the break
but you would have
them you build yourself
auto barometer if you do his mercury
you have a what you're on the time you
would see that level
go down in depression is highlighted
when it was good to get the precious
little
the weather was not so good for you
could build yourself a water brought
author has to be ten meters long
the story has a depasquale
most french
that the whole thing was red wine
we had a red wine bar barometer
it's very good to remember
meters of water
but there was a hypothetic pressure
or one atmosphere
if you go down into the ocean
five hundred meters
then dehundra static pressure increases
by ten atmosphere
every ten meter
is one atmosphere
cornelius palmdale
i know how to pronounce it me because i
am dot she was a dutch inventor
is you have a credit it
was building
the first submarine in the very early
seventeenth century around sixteen
twenty two
and he successfully operated this
submarine
at a depth of about five meters
measured five meters
the hydrostatic pressure there is hop on
atmosphere
ten meters
one atmosphere five meters
popping up to speed
nowadays submarines
go it's a little secret how far to go
but
they've got up to three thousand feet
which is nine hundred meters
ready hydrostatic pressure
is ninety atmospheres
on every square meter
all that submarine even is that
nine hundred meters
there is a forceful nine hundreds poems
nine hundred thousand
kilograms
oakland label submarine
orderly normative congressman for the
seventeenth century
because how are you going to see you
the vessel
but by the inside of the vessel
is one that mister yet
that's the air that he was breaking
expired meters
the local level
and cody outside
pressure is one-and-a-half atmosphere
maybe one atmosphere barometric pressure
and how fun atmosphere from the
hydrostatic pressure suzanne over
pressure on the vessel
atmosphere
that means
on every square centimeter that is a
force pointing inwards
of papa kilogram problem the public and
about weight
forces always perpendicular to the
surface and if you would take to square
meters all his submarine
that would be a force of ten thousand
chemical
amazing that he managed to do that and
that you could actually operates
this submarine
successfully
i can show you here twenty six one
hundred
what kinds of forces from the table
dealing with
you see there in front of you
that they can
and i'm going to evaporate
not separate i'm going to perpetuate h
do you think and i'm going to
bumped the arabs
so here is that they can
or twenty five seventy despite extinct
and sort of equivalent of one atmosphere
outside one atmosphere inside they can
it happen
i'm going to suck the air out
so i got on the pressure here
in other words
the pressure outside is higher than
inside exactly
the problem that from greta lad
pressure outside of high end in sight to
get a potion
he managed to conquer that to build
strong enough
when we talk take out the air here
you can argue well then the over
pressure is really what miss being the
only dealt with
often atmosphere well before every week
this to be vacuum believe me it already
implode
so reporters that we're dealing with a
very comparable
what from table with dealing with
when he built his suffering
and so does ken
will start to crumble
when we taking a route
that's another way of really seeing the
atmospheric pressure
i think the pressure of the inside
the can
literal beast
goalies
because of the
auction
hair
that is hanging on this and is pushing
down on us
that has to be properly sealed
there's always a bit of a problem
and so i have your vacuum pumps
and that's pump on it
you can already hear
the crushing
the force on the front cover alone if
he's free on that seventy five
square centimeters
if the pressure inside with zero that
will be a force of three hundred seventy
five kilograms
are very happy that can
and these are the kind of forces very
comparable to what food label
will be released
in the seventeenth century and he was
able to even operating submarine
under these forces without collapse
okay i think we've
one thicknesses souvenir
although i can give that you have to
first dictate this off
but you can't pick it up later
that
that mouthpieces quite precious for us
because we
at the use of the gamut quiz
so he would have tremendous forces his
art state when you do with
barometric pressure if you go scuba
diving
you go to a depth of ten meters
british ticket to open your mouth
we could go all the way to the surface
and put your brief
well there's no way
joy here
ever told
here is the water level
ambitious penniless
them
over pressure here
for your lungs
and the water is one atmosphere over
pressure
so here is one atmosphere
barometric pressure
here's what happens to hydrostatic
pressure plus the barometric pressure so
here we have to ethnicity
there was a huge force on your chest
inside you mon tues one atmosphere
outside store atmospheres
and there's no way
that you could
if the aerial mike chesterson thirty
back thirty seventy two fifty thousand
square centimeters
it would be like having a hard look at
graham wake on my chest and also my
backup
what direction like this
and it pushes like this at like these
i'd like this
from really being squeezed today
so what do you do when you go scuba
diving
yuri pressured hale wishing in effect
and after break
and so now we keep pressure there
you can obviously counter
hydrostatic pressure
now suppose
we go snorkeling
that's different
that we do have a little too
you don't know
and restore
how do you do you think we could norcal
that are long scoot easily accommodates
hydrostatic pressure
any idea
you think we could snorkel maybe three
years
who thinks we could legally do three
news
okay how are things
maybe only one leader
would face
my testimony
ollie north not way less because it's
not without this along to the both of
them
you know you can at least in thirty
seven e with ken deal not that much less
we can measure
how did we could snorkel
and we can measure
what the capacity of the capabilities
ovr lungs are in order to conquer
hydrostatic pressure
if i'm on the water there is pressure on
my chest
and so too
that reality tv
just are discrete that goes out
but in order to inhale sucking the air
i would have to
pooja out my chest
morris that powders
the force
due to be
and so the question is
what kind of pressure put tight generate
which my loans
to over
hydrostatic pressure
and we are going to measure that today
with an instrument that we call them the
model
molitor
is a simple through
could be made of anything the plastic
tube were fine
and we have liquid in here
it's open here
and open here
upon my mafia
and i'm going to see
how much over pressure
i can producing my lungs by pushing by
blowing
and so i'm going to blowing here
and then there's level will go down
and this level will go up
and his height difference
that's golden age
and the density only for a week
zero
little use water for that
call it water
for the pressure here
why wong
equals he won't
that's here
and the pressure here
like to
people speak to
and so people
minus beetle
equals
rope
underage
i apply
the law that we still have your people
might it be too
rope underage
i know that
into level is
one atmosphere
one atmosphere that's open
for the world
soapy bomb equals one atmosphere
was relates to you
and told my my my mother indicates
how much pressure i can generate
over and above the one atmosphere
and recall that opal pressure
with often work with over pressure
gauges
when you go to the
gas station and you have you file your
precious
measure depression in your bias is also
gates weaknesses overfished
so right there
we have such a mno mother
i'm going to blowing here
and that's going to tell is immediately
how deep my considerable
if i have avaible
to make it harder for us
ten liters
then i could
small coed at that point canoe used in
the water
because it means that i could generate
an awful pressure one atmosphere
it would only be five meters than i
could only snorkel bumper five meters
if you could only
said well neither
and i could really only point for the
reprieve
while meter below
and that's what you're seeing here
and i want you
ready you know it's hard for it to be
so fantastically filed away because it
would be longer
they had the level
that we have now
on this side is atmospheric pressure to
open their and on this site is also
atmospheric pressure it's open that's
quite a level that the same
this market fifty centimeters above
the two fifty below
so if i can generate over pressure in my
lungs one-tenth of an atmosphere
this one would come up fifty seventy
eight and this one would bring da fifty
felonies
that's one years old water
while many of the water is equivalent to
a ten-to-one atmosphere remember
coming of the water is one atmosphere
hydrostatic pressure
if i can manage that
that i can
generated over oppression in my own salt
tens of an atmosphere and i could
snorkel then adept
well neither
let me try
happen fast
obliterating possible
you can have it maybe for a few seconds
but not for very long
this is very disappointing
for you cannot even snorkel at one
leader someone else wants to try a apple
cup is also very hygienic
maybe some of you can do better
would a stronger i remember
now when you blow don't make the liquid
also late because then you can squirt it
out you should really try take a deep
rest and then
push as hard as you can
strongman
there were about uh...
while meter and twenty centimeters she's
great
how about
sucking air
how much under pressure could regenerate
in my life
well connected with this
instrument
i can go like this
and of course the liquid will go to the
way around
maybe i can do much better
in terms of under pressure bending over
personal that's fine
ought to say
a lot of the one leader
when you on the water
it's never a problem to live in a row
because due to the heart of predict
pressure
there's a porcelain you chester and i
think a relatively easy
the problem is
to expand you once again
to reissue chest
that means
the problem is that you can't
stuck in the year going towards reducing
and experiment that i did
that deployments howdy
you can snorkel in the water
and we found that it's about what meter
was not the blowing out but it is the
sucking in
this weekend
it is a true story
i said to myself keith
supports
i see someone
on the second floor i looked down
someone on the first floor having a
great colossal juice wine or whatever of
the year
and i would like to
still that by sucking it up with a
stroll
but i do that
the idea with ending
i will be standing here
question being unaware
this glass down here with some great
stuff in it
that would be my straw
i would just talk about
and i decided over the weekend
that this trial could not be much longer
then then about that won't be there
that you just saw that the on the
pressure
effect when you go to
supermarkets and you by yourself
sees the stuff for kids
you know that this can be done you can
suck up at least this is the maybe forty
fifty seventy two that you should be
able to do otherwise it wouldn't sell
them
but i didn't think that i could do much
more than a meter
and so i went to the supermarket
and i bought myself
the whois
and i bought the host of the two leaders
and i still don't hurt
in the kitchen
like this
uh... had to go out there
advantage to do it
and surprised me
so i went back to the super-majority
hardware store
got myself
estimator
anew for sure there was no way i was
going to do it so i went to do
second floor of my home
i can look down on the first floor
that's the way the houses built
i can't believe it
i can't believe it's y
i can suck so well
it looks like it's almost the violation
of what i showed you
and so
i need some help from someone
and i'm going to demonstrate
program can stealing someone's drink
which was just me with that
could you have to holds
maestro inept
joe as you see because i will go very
high
so you're organs to stand here and i
will throw you the
the hose in a minute
spend a little bit on the sides of the
class concealed
a few shortly
okay
here's my stroll
they put in there
now as i'm going to try to get this
liquid up to me
i'm going to think
about why
i can do that raspberry i could only do
what we have
or something very special doesn't know
where you
that in my long distance five mi normal
there's no way that i could have
happened
atmosphere under pressure in my mum that
is not possible
so somehow i don't know it was my lungs
and maybe i won't even make it in the
first place
i can't talk when i do it
i cannot talk
illegal
me
i drank tenderly jews believe it or not
think about all these and flying at home
it's fun by yourself
alternative and longer
now watch it
what's it hold it if i take my finger
off what do you think will happen with
the cranberry juice
we'll run down dead goes
thank you for your wednesday
