Chapter 14, Problem 21Q

To determine

To Explain:

Why a ${22}^{\text{o}}\text{C}$ day is warm while a swimming pool at ${22}^{\text{o}}\text{C}$

feels cool.

Answer to Problem 21Q

Solution:

Air is a poor conductor of heat and has a smaller heat capacity which reduces the rate of heat loss to the air is small.

Explanation of Solution

Air is a poor conductor of heat. Hence, the rate of heat loss from our body to the air is much less than heat loss from our body to the water. As we lose heat quickly in the water and feel cold.

Also, water has a high heat capacity, so as heat leaves your body and enters the water, the temperature rises for the water close to our body is small. Air has a smaller heat capacity, so the temperature rises for the air close to our body is larger. This reduces the temperature difference between your body and the air, which reduces the rate of heat loss to the air as well.