The discussion centers on the behavior of mercury in a glass thermometer when inserted into boiling water, specifically the initial drop in the mercury column before it rises. This phenomenon occurs due to the thermal lag in the glass, which initially absorbs heat through conduction, causing the mercury to contract before expanding. The participants note that such conceptual questions are unlikely to appear on the AP Physics exam, based on past exam experiences.
PREREQUISITESStudents preparing for the AP Physics exam, educators teaching thermodynamics, and anyone interested in the principles of heat transfer and thermal properties of materials.
How does the heat get to the mercury in the bulb? (ie. there are only three ways to transfer heat: convection, radiation or conduction). So what does the heat do to the glass?salemchic05 said:I have a concept question that asks, "When the bulb of a mercury-in-glass thermometer is inserted into boiling water, the mercury column first drops slightly before it begins to rise. Account for this phenomenon." I have no idea why. Any ideas?
salemchic05 said:I have a concept question that asks, "When the bulb of a mercury-in-glass thermometer is inserted into boiling water, the mercury column first drops slightly before it begins to rise. Account for this phenomenon." I have no idea why. Any ideas?