Passage III
A mercury thermometer, at an initial temperature of 20°C, was placed in 30°C water, and the temperature registered by the thermometer was recorded over time. This procedure was repeated using water samples at 40°C and 50°C (see Figure 1). Next, the same thermometer, at an initial temperature of 50°C, was placed in an air sample at 20°C, and the temperature registered by the thermometer was recorded over time. This procedure was repeated using air samples at 30℃ and 40℃ (see Figure 2).
(Note: Assume that the designated temperatures of the water samples and air samples did not change during the measurements.)
15. Based on Figure 2, for the thermometer placed in 30℃ air, the average kinetic energy of the mercury atoms in the thermometer was greatest at which of the following times?
Your Answer is
Correct Answer is A
Explanation
The average kinetic energy of the mercury atoms is the highest when the temperature is the highest, so look at figure 2, the line segment corresponding to air temperature 30°C, at 100sec, the temperature is higher than other options