A beachcomber finds a corked bottle containing a
message. The air in the bottle is at atmospheric
pressure and a temperature of 30.0°C. The cork has a
cross-sectional area of 2.30 cm2. The beachcomber
places the bottle over a fire, figuring the increased
pressure will push out the cork. At a temperature of
99°C the cork is ejected from the bottle.
• (a) What was the pressure in the bottle just before the
cork left it?
• (b) What force of friction held the cork in place?
Neglect any change in volume of the bottle.Solution
• Find the final pressure from