Chapter U5.3, Problem 2E

Interpretation Introduction

Interpretation:

The term thermal equilibrium needs to be explained.

Concept Introduction :

A stable situation or a state of balance where all the opposite forces cancel each other so that no alteration occurs is known as a state of equilibrium.

In a room, hot as well as cold air enter at the same time, and due to that, the overall room temperature doesn’t change. This is known as a state of equilibrium.

Answer to Problem 2E

When two substances are in physical contact with each other but no exchange of heat energy takes place, it is known as thermal equilibrium.

Explanation of Solution

It is known that the temperature is used to measure the coldness and hotness of a body. Two main concepts that impact the temperature are thermal equilibrium and thermal contact. Two substances are said to be in thermal contact if they affect the temperature of each other. Two substances are in thermal equilibrium when they are in thermal contact but their temperatures don’t change.

For example, if a milk carton from a refrigerator is kept on the countertop of the kitchen, then these two substances are said to be in thermal contact. After a few hours, they will contain the same temperature and thus will be said to be in thermal equilibrium.