21 December 2010 at 08:53 #15392
This can show a difference with remarkably cheap scales. The fizz-keeper works well and is probably worth the investment over cheaper versions but they too will show that air has mass. As well as pumping it up you can also buy similar items that remove the air from wine bottles. By placing a semi-inflated balloon or marshmallows in a pop bottle and removing some of the air you can see the effects of air pressure imbalances. Marshmallows in a bell jar connected to a vacuum pump are also an interesting demonstration.
Themes: Gases, forces