Arrival Craft: Air colouring sheet. air
Introduction: Gasses can be compressed more than liquids or solids, but there are still limits. If we try to squash air too much, it will rush away.
If I blow up a balloon and let go of the end, what will happen?
The air will rush out of the balloon. The force of the air rushing out will push the balloon away in the opposite direction. This is one of the big rules of energy: every action has an equal and opposite reaction.
If you inflate a balloon and attach it to a CD, then the air will rush out through the hole, pushing the CD into the air, like a tiny hovercraft. These are easy to make, but there’s a YouTube video on @Bristol’s site, which is very good. https://www.at-bristol.org.uk
Individual Task: Make CD hovercrafts.
Break for drink and snack.
Second Part: If we don’t give the air any way out, then we can use it to push things.
This is called pneumatics.
Individual Task: Make pneumatic hoists out of tech card.