Chapter 28, Problem 6Q

To determine

When placed in a hot bowl of soup, does the temperature reading of a thermometer be equal to the temperature of hot soup before the measurement.

Answer to Problem 6Q

Solution:

The temperature readings when measurement is made are slightly lower than the non-measured readings when the thermometer was placed in the hot bowl of soup.

Explanation of Solution

A thermometer contains mercury inside of it. When put in the hot soup, the mercury is heated up to the temperature of the bowl and heats up. Since all materials expand on heating, it starts to rise along the temperature scale. Finally, when the temperature of the bowl is equal to the temperature of the mercury inside the thermometer, it stabilises and we note the temperature.

It is clear from the mechanism detailed above that some heat is supplied to the thermometer from the bowl. The thermometer fails to detect the temperature before measurement, and the readings taken are slightly lower than the non-measured values.