(Sound of bubbles popping) G’day, I’m David from the Questacon
Science Squad and people have been telling me my whole
life I’m full of hot air. So it’s about time that I decided
to do something about that and put that hot air to good use.
So, I decided to make a balloon-powered car. For this I’m going to
need a piece of cardboard about 8cm by 10cm, obviously
a balloon, a couple of skewers, 3 straws, two
straight straws and one with those nice bendy bits in it.
We need 4 bottle tops, about the same size
is great, they’re going to be our wheels, some
scissors, a piece of elastic band, and last but not least
some sticky tape. Alright this is what you do: grab your straight pieces of
straw and place them on the bottom of your piece of cardboard there, just
like that, you want them just about even. Grab some sticky tape and stick them down.
There, great. One piece down… two pieces down.
Flip that over. Now, your skewers are going
to be your axles and then that’s what your wheels are
going to go on the end of. So your wheels should already have a
couple of little holes drilled in them, they want to be about the same
size as the thickness of our skewer. So stick that in one end, there we go, just like that, through the axle. Ooh no, wait a second, we want to put
these around the other way so that rough bit on the side of the bottle
cap doesn’t catch on the cardboard. Same on this side,
just push it through. There we go, beautiful.
And we’ve got a second one. Try not to stab yourself in the hand
with the pointy bit at the end of the skewer, I’m told it really hurts.
I wouldn’t know by personal experience of course, I’m not silly enough to do that.
Alright, get that one on. There, great. Alright, now, the next part, take your bendy
straw like this and your balloon and your scissors and cut your bendy straw so you’ve
got two pieces about the same length. There we go. Beaut, so you’ve
got a nice little bendy piece like that.
You can get rid of that, over you go. And take your balloon on the end of one section
of the bendy straw, elastic band on the outside, and just wrap
it around a few times, so the balloon stays onto
the end of the straw. It should end up looking
something like this. You should be able to blow it
up and no air gets out of it. Alright, now back to your wheels,
it takes a little bit of working out to try and get these straight
so the car moves forward nicely. So I’ve made one a little bit
earlier, which I’m sure works. Here it is. It’s a beauty, isn’t it?
Nice, orange wheels. OK, so grab your balloon and your
straw, get another piece of sticky tape like that and put it on the
end of your straw like there, and stick it down so the end of
the straw is poking out over the side of the car and your balloon’s
stuck in the middle of it. Now it’s time to test how it races, so get
your balloon and start to blow it up. And you might notice that
I’ve chosen a red balloon, that’s because everyone knows
that red is the fastest. Alright, let’s see how it goes.
3, 2, 1, balloon car away! Look at it go! It’s brilliant, isn’t it? If you want to find out more about
making a balloon car, you can head on down to the Questacon Science Squad website.
I’ll see you next time.