Water if 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?
A) 2 cm3 B) 3 cm3 C) 12 cm3 D) 18 cm3
Solutions: Option A
Since the air bubble is enclosed, PV at A is equal to PV at B.
PAVA = PBVB
(Patm + Pwater) VA = (Patm) VB
(10 + 20) VA = 10 x 6
VA = 60 / 30
= 2 cm3