A diver uses an air cylinder with a volume of 11 L and filled to a pressure of 200 atm (...

A diver uses an air cylinder with a volume of 11 L and filled to a pressure of 200 atm (Fig. P15.52). He dives at a leisurely pace, taking about 15 breaths per minute, and each breath is 1.2 L on average. (a) If he must leave 17% of the air for reserve, how long can he dive at 20 m deep? Hint: The pressure must be considered as in Problem 51. (b) How long will his air supply last if he dives at 30 m? Approximate air as an ideal gas.

(reference problem 51)

A scuba diver descends to 8.2 m below the surface of the ocean. (a) What pressure will her regulator need to supply so that her lungs can fill as normal? (b) When the diver is at 8.2 m, how many times more molecules of air are in her lungs than at the surface? Treat air as an ideal gas and assume the temperature is the same in both instances, which will be somewhat less than body temperature.