Question

3. At the end of a warm summer day, imagine you are jumping from the 80°F air into an

80°F swimming pool. Use what you have learned about thermal energy and heat flow to
explain which direction heat from your body flows in the air and in the water, and why the
pool feels cooler than the air. (10 points) Think about the temperature of your body and the
factors that determine whether a substance makes a good thermal conductor,

Answer 1

• 1. Since the temperature of your body is higher than the temperature of the air and of the water, heat will flow from your body to the air and pool.

• 2. The pool feels cooler than air because the water can absorb heat energy faster than the air, due to liquids are better conductors than gases.

Step-by-step explanation:

Heat always flows from warmer substances to colder ones.

The normal body temperature is 98ºF. Therefore, the heat will flow from your body to the air and pool, which are at a lower temperature of 80ºF. In both cases, you will lose thermal energy and the external parts of your body will cool down.

The difference between both cases is in the heat conduction capacity of both air and water.

Liquids (and solids) are better thermal conductors than gases because the conduction of heat occurs as result of the direct contact between the particles of matter: the atoms or molecules in hot matter vibrate faster than their neighbors and transmit them kinetic energy by direct contact.

Therefore, the liquid water in the swimming pool, at the same temperature than the air, will be able to absorb more heat in the same time from the body.

In conclusion, the body will cool down faster in water than in air which is why the pool feels cooler than air.