Human lung capacity varies from about 4 L to 6 L, so we shall use an average of

Question

Human lung capacity varies from about 4 L to 6 L, so we shall use an average of 5.0 L. The air enters at the ambient temperature of the atmosphere and must be heated to internal body temperature at an approximately constant pressure of 1.0 atm in our model. Suppose you are outside on a winter day when the temperature is -9.0 F.

Part B

How much heat must your body have supplied to get the 5.0 L of air up to internal body temperature, assuming that the atmosphere is all N2?

Express your answer in joules to three significant figures.

Part C

Suppose instead that you manage to inhale the full 5.0 L of air in one breath and hold it in your lungs without expanding (or contracting) them. How much heat would your body have had to supply in that case to raise the air up to internal body temperature?

Express your answer in joules to three significant figures.

_____

Explanation / Answer

Part B)   heat must your body have supplied   = n * Cp * T

                                                                       =    (1 * 5)/(0.0821 * 250.372) * (7/2) * 8.314 * 59.778

   =    423.11 J

Part C)    heat would your body have had to supply in that case = n * Cv * T

                                                                                    =    (1 * 5)/(0.0821 * 250.372) * (5/2) * 8.314 * 59.778

      =    302.22 J

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.