Chapter 21, Problem 50A

Suppose that water is used in a thermometer instead of mercury. If the temperature is at $4°C$ and then changes, why can’t the thermometer indicate whether the temperature is rising or falling?

To determine

To explain: The reason for not indicating the state of temperature by a thermometer.

Answer to Problem 50A

Thermometer does not indicate the state of temperature by a thermometer because at this temperature, cooling or heating is indeterminate.

Explanation of Solution

Introduction:

Water has a high freezing point as compared to Mercury.

If a water is in the thermometer, then as soon as it reaches $0°\text{C}$ . It will tend to freeze the thermometer. Thus, computing temperature falling or rising at $4°\text{C}$ is indeterminate.

Conclusion:

Thus, it is indeterminate if temperature rising or falling at water $4°\text{C}$ .