In cold weather, you can sometimes “see” your breath. What you are seeing is a mist of small water droplets, the same as in clouds and fog. Suppose air leaves your mouth with temperature 35^oC and humidity 0.035 kg/m³ and mixes with an equal amount of air at 5^oC and humidity 0.005 kg/m³.

(a) What is the relative humidity of the mixed air if its temperature and humidity equal the averages of those of the two original air masses?(b) Represent what happens by plotting three points in a graph like Figure 5.34.

In Figure 5.34

Transcribed Image Text:

Density (kg/m) (a) 0.05 0.04 0.03 0.02 0.01 0 -10 20 Liquid 0 40 T (F) 60 10 20 30 T (C) condenses to 80 100 freezes to decreasing PE decreasing PE 40 Phase transitions where Gas Solid Density (kg/m) (b) 0.05 0.04 0.03 0.02 0.01 0 -10 evaporates to increasing PE increasing PE 20 0 melts to 40 T (F) 60 Saturation density 10 T (C) Liquid 80 20 30 100 40