Chapter U5.96, Problem 9E

Interpretation Introduction

Interpretation:

Evidence that supports second law of thermodynamics needs to be provided.

Concept Introduction :

According to the second law of thermodynamics, entropy of the universe always increases.

Answer to Problem 9E

Heat always flows from higher temperature regions to lower temperature regions; the brakes of the car change its kinetic energy to transfer heat to the environment.

Explanation of Solution

As per the second law of thermodynamics, the entropy of universe is always increasing for any spontaneous process.

Or,

  $\Delta {\text{S}}_{\text{univ}}>0$

As per the second law of thermodynamics, energy is dispersed but it is not concentrated. The heat transfer from an object having higher temperature to a lower temperature object cause higher randomization of energy which was concentrated within the hot object and then is dispersed between the two objects.

During the flow, heatmoves from lower to higher temperature object and thus decreases the entropy.

But according to the second law of thermodynamics, entropy should always rise. Thus, the heat always flows from object having higher temperature to lower temperature that results in the rise in entropy.