Solution Found!
BIO Work Done by the Lungs. The graph in Fig. E19.4 shows
Chapter 19, Problem 4E(choose chapter or problem)
The graph in Fig. E19.4 shows a pV-diagram of the air in a human lung when a person is inhaling and then exhaling a deep breath. Such graphs, obtained in clinical practice, are normally somewhat curved, but we have modeled one as a set of straight lines of the same general shape. (Important: The pressure shown is the gauge pressure, not the absolute pressure.)
(a) How many joules of net work does this person’s lung do during one complete breath?
(b) The process illustrated here is somewhat different from those we have been studying, because the pressure change is due to changes in the amount of gas in the lung, not to temperature changes. (Think of your own breathing. Your lungs do not expand because they’ve gotten hot.) If the temperature of the air in the lung remains a reasonable \(20^{\circ} \mathrm{C}\), what is the maximum number of moles in this person’s lung during a breath?
Questions & Answers
QUESTION:
The graph in Fig. E19.4 shows a pV-diagram of the air in a human lung when a person is inhaling and then exhaling a deep breath. Such graphs, obtained in clinical practice, are normally somewhat curved, but we have modeled one as a set of straight lines of the same general shape. (Important: The pressure shown is the gauge pressure, not the absolute pressure.)
(a) How many joules of net work does this person’s lung do during one complete breath?
(b) The process illustrated here is somewhat different from those we have been studying, because the pressure change is due to changes in the amount of gas in the lung, not to temperature changes. (Think of your own breathing. Your lungs do not expand because they’ve gotten hot.) If the temperature of the air in the lung remains a reasonable \(20^{\circ} \mathrm{C}\), what is the maximum number of moles in this person’s lung during a breath?
Step 1 of 5
According to the ideal gas equation,
pV = nRT
Here, p is the pressure, V is the volume, n represents the number of moles, R is the universal gas constant, and T is the temperature.
Step 2 of 5
Work done is the area under the pV -diagram.
Consider the following diagram,
Step 3 of 5
The y-axis pressure (p) is plotted, and the x-axis volume (V) is plotted.