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.)
13. When the thermometer was in the 50℃ water, in the time interval between 2 sec and 3 sec, approximately how rapidly, in℃/sec, was the temperature registered by the thermometer changing?
Your Answer is
Correct Answer is B
Explanation
Look at figure 1, when the abscissa is 2.0 sec-3.0 sec, the ordinate range corresponding to water temperature 50°C is about 41°C-45°C, so the temperature change in this second is 45-41 =4°C