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(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.