What it shows
Pulling the diaphragm (the stretched balloon) down makes more space in the chest, the air pressure inside drops, and air rushes into the lungs. Pushing it back up pushes the air out.
This idea has a short entry only. For the science behind it, read the sentence above with your textbook and ask your teacher to explain the law or idea it shows, so you can describe it in your own words.
Materials
- A plastic bottle with the bottom cut off
- Two small balloons as lungs
- A Y-shaped connector or two straws
- A large balloon as the diaphragm
- Clay to seal the top
Safety
For this project: An adult should cut the bottle.
Never use mains electricity: power models with cells, batteries or a low-voltage adapter. Sharp and hot tools, flames and lab chemicals need an adult or your teacher beside you. Keep magnets, button cells and small parts away from young children, and wash your hands after making.
All the safety rulesHow to go about it
Numbered steps have not been written for this idea yet. Plan it with your teacher: sketch the design with measurements, build one part at a time, test each part, and write every observation with the date. The free ebooks below have step-by-step projects of the same kind.
Free ebooks for this project
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