Question from http://www.sgforums.com/forums/2297/topics/330790
TYS D04/P1/Q15
Water of depth 10 m exerts a pressure equal to atmospheric pressure. An air bubble rises to the surface of a lake which is 20 m deep. When the bubble reaches the surface, its volume is 6 cm3. What was the volume of the air bubble at the bottom of the lake?
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Answer:
Many of my tuition students asked this same question, so I think it would be great for me to post it here to share. It's an MCQ question, but I won't be posting out the choices, because it can easily be turned into a structured question anytime.
At the surface:
Pressure, P1 = 1 atm (atmospheric pressure equivalent to 10m of water), V1 = 6cm3
At the bottom of the lake:
pressure, P2 = 3 atm (atmospheric pressure + 20 m of water), V2 = unknown
Using Bolye's Law, P1V1 = P2V2
V2 = 2 cm3
