♪ [upbeat music]
(Jonathan Jerome) Hello. Welcome to Cool Science.
My name is Jonathan.
We're here in Space Place today at Science North
and I'm gonna show you the science of rocket fuel.
Now the simplest rocket is really just a balloon.
You've got your container for the fuel,
you've got the nozzle where it comes out.
If I blow up this balloon,
it's full of air.
And all that air wants to escape
and there's only one place for that air to come out.
When it comes out the bottom,
the balloon is gonna go up.
This is something called Newton's third law of motion.
For every action,
there's an equal and opposite reaction.
If the action is the air coming out,
the reaction is the balloon going up.
So let's launch this rocket.
Ready for lift off?
Three, two, one.
So real rockets are a lot heavier than a balloon.
So they need a stronger force to get them into the air.
A force is called thrust.
Instead of just compressing gasses inside a balloon,
they actually burn them and combust these gasses.
And all of the heat and energy from that combustion
rushes out the nozzle of the rocket.
So we're gonna make some of that fuel.
Here I've got a little container full of salt water
and I'm gonna run some electricity through it.
When I do, that electricity is going to change the water.
It's gonna break it apart.
[whirr]
So as I'm cranking this,
there are gonna be little bubbles
coming out of the ends of the pencils.
These are the electrodes in the water.
And those bubbles are the gas
that we're gonna use for our rocket fuel.
[whirr]
To show you what's happening to the water,
I have a little tiny model here.
So water is also known as dihydrogen monoxide,
or H-2-O.
What that means is that we have two atoms of hydrogen
attached to one atom of oxygen.
Now when we're putting electricity into the water,
we're breaking apart the water,
breaking apart the bonds between the atoms
so that the hydrogens stick together and become a gas
and then the oxygen becomes a gas, too.
So for every two molecules of water,
we get two molecules of hydrogen gas
and one molecule of oxygen gas.
So I've got a bigger machine over here
that's doing the very same thing.
I'm running electricity through
a little container of water here
and it's breaking it apart into the hydrogen gas and the oxygen gas.
I'm collecting it in this tube
and then I'm gonna let both of those gasses mix together in this bag.
I think we should be just about ready.
Now we'll see just how much energy is contained
inside this tiny amount of those two gases,
hydrogen and oxygen.
Ready for lift off.
Three, two, one.
[blast]
So you can hear and see the power that came from
just a tiny amount of those two gases mixing together.
Now, imagine an entire rocket full of hydrogen and oxygen burning together.
And you've probably seen
all this smoke coming out of the back of a rocket when it launches.
And it looks like an awful lot of pollution,
but think about what we're combining.
We had our hydrogen and our oxygen
and when we burn them together,
we're getting back all of the energy that it took
to break those bonds and separate them.
And the end result is water.
And that is rocket science.
I'm Jonathan.
Thanks for joining me on Cool Science.
See you next time.