Problem 27E
An electric fan not only doesn’t decrease the temperature of air, but it actually increases air temperature. How, then, are you cooled by a fan on a hot day?
Step-by-Step Solution:
Solution 27E Step 1 of 1: The fan does not affect the actual temperature of the surrounding. But it just helps the sweat on the human body to evaporate by blowing air over the skin.While evaporating, water takes the heat from the human body. This evaporation results in cooling effect on the human body, as it takes away the heat. On a hoter day, as water has high specific heat, it requires more heat energy to evaporate; so it consumes more heat from the skin of human and evaporates fast with the help of blowing fan and hence the fan keeps us cooler even on the hot day.
Step 2 of 1
