Hi everyone, I'm Emily and today we are
creating a vortex ring in a bottle. for
this one you need a plastic bottle some
scissors a balloon and something that's
going to create smoke or fog. you can use
matches or incense.. I think my parents
lit a bit of a newspaper on fire and
that create smoke, you could use a fog
machine. either way you're going to need
adult supervision for this. there's gonna
be some smoke and maybe flames involved
so please be careful. the first thing you
want to do is take your bottle and cut
the bottom off like right there just
like so...then take your balloon and cut
that skinny part off right there then
take your balloon and put it over the
bottom part of your bottle just like so.
next take a match or whatever you're
lighting to create smoke or fog, light it
blow it out, and then stick it in your
bottle wait for that smoke to build up
and then tap the bottom of your bottle
okay I had to put up a darker background
so that you can see these smoke rings
check it out
I could do this all day long
what's going on here well essentially
when we hit the back of our bottle we
are pushing out a ball of air but that
ball there is really interesting because
the air in the center of that ball - in
the center of our bottle - is moving
really really fast and because of
Bernoulli's principle because it's
moving faster that means it's creating
lower pressure now the area around that
fast-moving air along the perimeter of
our bottle is slower. why is it slower?
well it's getting slowed down because
it's touching the edges of the inside of
this bottle and it's being slowed down
by friction. because it's slower moving
air it's an area of high pressure. so we
have an area of low pressure surrounded
by an area of high pressure - this
generates a flow pattern that's creating
vortices. vortices just means spinning
air (a fluid) so we're creating spinning air all
around the outside of that opening
that's creating a donut ring of
vortices
and that's how you create a vortex ring
in a bottle!
next take a match or
whatever you...whoops
