Kind: captions
Language: en
[Applause]
[Music]
hey n can you get me another Coke no I'm
good things it's just downstairs no the
tennis is on you come to my house to
watch the tennis and you're not even
going to get me another Coke yeah but
it's a tiebreaker relax you know what I
wish we had like a really long straw so
we don't even have to go downstairs to
the kitchen that would be pretty good
yeah right how long of a straw could we
actually make that you could
use downstairs would be a bit of a
stretch I reckon yeah yeah don't think
we could is that like 3 4 MERS or we
could do it we need a lot of straws
though I got a pack here H okay now our
first test just to see that Nigro can
use a straw properly uh we've got about
a 1 M length of straw here you think you
can suck through that yeah that's good
we go so we just take these um drinking
straws together and
hopefully yeah that's all right well
there's a lot of air coming through I
think from the the joins and the straws
we've got to come up with some better
way to test this
out uh I happen to have 6 M of plastic
tubing here
nontoxic uh that's what they said at the
hardware store all right we're preparing
the preliminary test Nigel is lowering
some tubing off the balcony he actually
thinks he's got a shot at sucking
through 6 M worth of tubing I think he's
got no chance and it's going to be
nowhere close but this will hopefully uh
allow us to establish how much Nigel
actually
sucks he's getting ready up there he he
knows there's a lot riding on it when
you're
ready whoa look at that look at that oh
he shoots up he's got 2 m he's got three
M look at that guy go he's getting four
M four M five 5 M
yeah now I'm going to try to do the same
thing but the tube I'm using has a
thicker diameter mine is about uh 5 mil
whereas nig's was 3 mil so we're going
to see if this makes any
[Music]
difference now I guess the obvious
question is can Nigel do it
N I think that's the obvious answer but
I'm pretty sure he's going to fail uh
but maybe what we're talking about is
how straw works in the first place how
does it work yeah cuz this is really
just a big Bendy straw if we look at a
smaller version of a straw here uh we
should all be familiar with how this
works or should we I don't know I think
most people just think you were sucking
the liquid in and swallowing it but you
kind of have to think about air pressure
yeah because what is actually happening
is that air pressure is what's causing
the Coke in this case to go up the straw
well there's a difference in pressure
between the atmospheric pressure and the
pressure that you create by opening up
your lungs and pulling your diaphragm
down so you reduce the pressure in your
mouth and it's that difference in
pressure between the atmospheric
pressure and the pressure inside you
which gets that liquid flowing into you
it's a bit like high jump and like
someone has failed at the 5 mm diameter
and then you're the next guy to take it
on you ready for this I am ready he's
been practicing his whole life for this
okay you can see it's a strong start
strong strong start from Quan he's got
it oh he's he's he's going big right
here you can see there's a lot of
determination oh he's getting close he's
getting close look at this look at this
can he do it can he do
it oh he's done it God ah okay
disgusting yeah I definitely felt like
my tongue while I was trying to suck it
up was being pulled P out into into the
straw I felt the same thing yeah but and
it was tougher definitely tougher well
done sir thank you it means a lot for
his next challenge we're going to try to
get him to suck through 10.3 M which is
the theoretical maximum size of straw
how are you feeling well that
theoretical maximum kind of relies on
being able to get a perfect vacuum and
although I am perfect in a lot of ways I
don't know that I can create a perfect
vacuum I've often thought that there's
actually a perfect vacuum inside Nigel's
head
today we're going to really find out
won't we yeah okay we've got the setup
here we're down at tamarama Beach and we
have 10 1/2 M worth of tubing which goes
all the way up to Nigel at the very top
there so we're going to see if I can
relieve some of my former glory and get
the red liquid up this height 3 2
1 there you have nyel is starting to
suck on on that
straw there he
goes looking strong create that vacuum
approaching the edge of a cliff there Go
Nigel go come on
Nigel doesn't seem to be going anywhere
we seem a bit stuck and that point right
there you can see the determination the
focus trying to see how high that is
he's done
well but it just doesn't look like it's
going to
happen
[Music]
all right so Nigel did pretty well there
we saw that he could uh get the Liquid
up that tube about 7 m not the
theoretical maximum of 10 m still more
than you that's a good point that's a
good point if Nigel could have created a
perfect vacuum then the water would have
gone up to 10.3 M by our calculations
this is kind of similar to how they used
to measure atmospheric pressure in the
old days by millimeters of mercury so
atmospheric pressure would push Mercury
up a tube with a vacuum at the other end
uh 760 mm 760 mm so about 76 of a meter
so you can see why they would have used
Mercury and not water because if you
were doing this with water you'd need a
cliff yeah you'd need a 10 m long uh
barometer so yeah much better to do it
with millimeters of mercury and of
course nowadays we measure it in kilop
pascals anyway well done Nigel you
really
suck so how do we work out the maximum
length of straw that you could suck
through vertically well think about this
you place a straw into the liquid and
you start sucking from the top that
decreases the pressure at the top and
the difference in pressure between your
mouth and atmospheric pressure creates a
force that pushes the liquid
upwards now that liquid which is in the
straw has a weight which is equal to the
volume of the liquid times its density
times the gravitational field strength
so if we set these two forces equal to
each other you see that the pressure
difference must be equal to the density
of fluid time its height time the
gravitational field strength and if we
sub in the numbers we find that the
maximum height of liquid that anyone
could theoretically lift even if they
created a perfect vacuum inside their
mouth would be about 10.3
m