Hello I am Jared, welcome to Fun Science
Demos. You know, if you stop and think
about it, you can find science almost
anywhere. In fact there is a lot of
science in a simple blown up balloon.
Watch what happens when I let it go.
It flies away!
Well, what kind of science is
at work there? Now it took a force to
make this balloon move, and a force is a
push or a pull, so that means the balloon
was pushing against this table. It was
pushing against the air. It was even
pushing against the pull of gravity.
Forces at work! We decided to use the
forces at work in this balloon to create
a design challenge, and just like this
balloon had to push against this table
in the air and the pull of gravity.
Rockets have to push against the ground
and push against the air and push
against the pull of gravity.
Now, most rockets have two sets of
engines to get the rocket past the pull
of gravity. In this case I only had one
balloon or one part of my rocket. For our
design challenge we are going to try
connecting two different balloons
together to act like a two-stage rocket.
Now balloons come in all different
shapes and sizes and we have experimented
again and again to find out which
balloon works best for this design challenge,
and we figured out that the
medium-sized longer balloons tend to
work best but that does not mean you
cannot try all the different shapes.
That was a lot of fun, and I think we are ready
to actually show you how this works.
To make our two-stage rocket. We need two
balloons those balloons are going to be
our power source and to hold them
together all we are gonna need is a cup.
It is a very simple building process to
start I needed to cut a hole in the
bottom of the cup and you noticed I put
tape around that hole because we found
that those edges, those rough edges, would
pop the balloon when we tried to pull
the one balloon into the bottom of the
cup. Simple process. So the next step is I
have to blow a balloon up
I like to stretch them out to make them
easier to blow up. If you need an adult
to help you blow it up that works too.
So here we go.
That is the front part of
my rocket and now what I'm gonna do is
pull it through the opening of the cup
so that I stretch the end of that
balloon and I can wrap it around the
bottom part of the cup now what is gonna
happen is I am going to blow up the other
balloon inside the cup, and the force of
the air pushing out should hold that
balloon shut. I'm ready to go so now I am
ready to blow up the second part of my
rocket. Now remember I am holding this
balloon with that finger and I am gonna
blow it up.
When I pinch it look what happens! The force of the air pushing
inside the orange balloon keeps the blue
balloon shut. So think this through:
What do you think will happen when I let go of the orange balloon?
Well as I let go of the orange balloon, the air inside the
balloon makes the balloon gets smaller,
which should release the blue balloon
and I think I have a two-stage rocket
ready to go. So I am going to walk you
through slower so you can see how this
works and I am going to hold on to our rocket.
Now what is happening is the
orange balloon is inflated so it is
pinching the blue balloon so it is
holding it, it is holding it steady.
I'm going to slowly let the air out of the
orange balloon and you watch what happens
when enough air leaves the balloon.
You could see as the orange balloon deflated it let the blue balloon go and we had our two-stage rocket.
Alright, we are set for launch. Let us see
what happens. You are clear for takeoff.
Here we go! Three, two, one!
That was almost as cool as a real NASA
liftoff. We actually blew our balloons
back up so we could rebuild our
two-stage rocket so we could talk about
what happened. If you think about what
you saw I saw the first part of my
rocket the orange balloon lift our
rocket off the ground and then when all
the energy was out of that balloon the
blue balloon took over and flew even
further. It is a two-stage rocket design
that we built here in our classroom.
Now, we had a lot of fun with this design
challenge because we tried all these
different balloons. Well...
try making a two-stage rocket and you
try all these different balloons. Try a
big balloon! Try a small balloon and see
which one works the best. You can time it
to see which one stays in the air the
longest which one goes the highest which
one goes the furthest.
It is a really cool design challenge that you can do with
very simple materials.
If you want to learn more about science or other design
challenge ideas like this check out our
channel. Sometimes you just have to stop
and try and wonder why.
Thank you for watching!
