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Experiment air2:
Influence of pressure on the volume of air


* Left photo: Three-quarter fill a 100-ml vial with water.
* Add 0.3 ml of water to a 1-ml vial.
* Place the small vial bottom-up into the big one.
* Close it by a stopper punctured by a 20-ml syringe with
   an injection needle.
* Press air from the syringe to the air locked above the water.
* Right photo: Disconnect the needle from the syringe to remove the air from the syringe, reconnect the syringe to the needle.
* Suck from the air locked above the water into your syringe.
Observation left:  The volume of the air bubble in the small vial is reduced by the positive pressure put on  the water.

Observation right: The volume of the air bubble in the small vial increased due to the negative pressure put on  the water. So water is pressed out of the small vial resulting in its floating.
Explanation: As the water in the vial is not compressible, the positive and the negative air pressures are transferred to the air bubble in the small vial reducing and increasing its volume.
(You can feel on your eardrums that the air pressure changes while you are quickly moving on a mountain or back).
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