Chapter 4.5, Problem 73PE

An adult human at rest inhales and exhales approximately $500\text{ mL}$ of air (called the tidal volume) in approximately $5\sec$ . However, at the end of each exhalation, the lungs still contain a volume of air, called the functional residual capacity (FRC), which is approximately $2000\text{ mL}$ . (See Example 6)

a. What volume of air is in the lungs after inhalation?

b. What volume of air is in the lungs after exhalation?

c. What is the period of a complete respiratory cycle?

d. Write a function $V\left(t\right)=AcosBt+D$ to represent the volume of air in the lungs $t$ seconds after the end of an inhalation.

e. What is the average amount of air in the lungs during one breathing cycle?

f. During hyperventilation, breathing is more rapid with deep inhalations and exhalations. What parts of the equation from part (d) change?