Chapter 12, Problem 79RPP

The bag and pump have a 6.76-kg mass. The volume of the inflated bag is 0.476 m³. The maximal bag pressure is 0.15 x 10⁵ N/m² above the air pressure at the site where it is used. In the 1997 climb, with the temperature at -20°C, the bag was filled in about 2 min with 10-20 pumps per minute. This raised the pressure in the bag to 0.58 x 10⁵ N/m² (equivalent to an elevation of 4400 m) instead of the actual outside pressure of 0.43 x 10⁵ N/m² at the 6450-m elevation at which the climber was treated. The treatment lasted for 2 h, with the climber inhaling about 15 times/min at about 0.5 L/inhalation, and was successful-the pulmonary edema disappeared.

What is closest to the temperature at the 6450-m elevation on the day described in the problem?

a. 37 K

b. 253 K

c. 20 K

d. -20 K

e. 273 K