OK, it's time to set sail with another great episode of Hub Lab with Phil of Science on Home School Hub!

This time there is water involved so we will ask you to not make too much of a mess as Phil explains to us how a boat floats. We will make a little paper boatr, but the same rules apply even for MASSIVE ships.

What are we going to learn?
1.Air pressure and force
2.How boats float
3.How diving bells work
4.How folds in paper give rigidity

Watch the video below to learn how to make your own boat...

Why do boats float again and how did you do that trick?
Firstly, it's not a trick – it’s science! Secondly boats will float if their shape pushes away more water than they weigh ie they are less dense that the water that surrounds them. Imagine a blown-up balloon. It weighs next to nothing compared to its size (the amount of water it pushes away) so it floats on water.

A boat is the same if the hull, pushes away more water than the weight of the boat – it floats! Which is why our paper boat sits proudly on the top of the water in the tank. The "trick" to get the boat to go underwater without getting wet is to have an air tight container big enough to fit over it. Air is made up of matter and therefore takes up space.

When you pop the container down over the boat it is filled with air. Air is less dense than water so it wants to rise up in it (picture how a bubble behaves) so it stays inside the container / glass. As there is air already inside the container with no way of getting out, the water below can’t force its way in so the boat floats on the water that’s below it and hence you can get your ship to sail underwater.

This is the exact way that diving bells work and how workers used them to engineer a lot of the infrastructure and buildings in water.

There's much more about the experiment in this activity sheet below!