In this lesson you can use the example of scuba diving to investigate how water pressure increases with depth and the effects that this has on the human body. To kick off your learning you can watch an amazing video on free diving and water pressure on the human body. You can then what you have learnt to explain how diving bells and/or submarines work out in the real world, and make your own (very) mini submarine.
The below video shows an incredible free diver who dives below what is normal. Usually divers cannot dive below 50m due to the danger of water pressure upon the body!
Having watched the video, you should now have some understand of air and how the density of air affects buoyancy. Submarines use a similar principle, as by altering the amounts of water and air in the submarine, the vessel can sink or float. Try making your own submarine in a bottle with the instructions below: