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Q & A: pressure and volume under water

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Most recent answer: 01/21/2012
What would the air pressure inside an upside down cup 20 meters under seawater be to keep the water out of the cup, at least sewen eigths of the water
- Obie (age 66)
Bloemfontein Free State RSA
No. The pressure goes up about 1 atm for every 10 m depth. So at 20 m depth it's about 3 atm. Since at fixed temperature the volume of a gas is about inversely proportional to pressure, the air will only fill 1/3 of the cup.

Mike W.

(published on 01/21/2012)

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