Air pressure demonstrations:

1. Place 1-2ml methylated spirits in small plastic bottle, and place in water bath of boiling water (heat water bath on hot plate as meths is flammable).
Continue heating until vapours of meths are seen. Take bottle from water bath and quickly put cap on. As it cools, the bottle is crushed. Can be done with water but meths boils at a lower temperature and so the process is quicker.
2. Place a small amount of water in a soft drink can and heat on a hot plate or with a Bunsen burner until steaming. Plunge quickly into cold water, hole side down.
3. Use an old olive oil tin. Put a small amount of water in it, and heat on a hotplate or Bunsen with the lid off. When I comes to the boil, turn off the heat, place the tin on a heat proof mat, close the lid and pour cold water over.
4. Make it really spectacular and use 44 gallon drums. Get them free from drum recyclers. Do it outside, supporting the drums on some bricks and use a gas ring burner of the type you can get in a camping store to heat the water. The drums have a small amount of water, 10 cm or so, and bring to a vigorous boil. Turn the gas off, close the lids, and hose down. Drums collapse wonderfully!

Leave a Reply

Your email address will not be published. Required fields are marked *