A student investigates a solid rock sample to estimate its specific heat capacity
PHYSICS · Multi-part · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter
Problem
A student investigates a solid rock sample to estimate its specific heat capacity. The sample is fitted with an electrical heater of known power output. A digital temperature probe embedded in the sample records its temperature every 10 s while the heater operates. The student observes that, starting at 18 °C, the temperature of the rock increases linearly with time until about 160 s, after which the slope begins to decrease and finally levels off.
Answer the following about the design and interpretation of the experiment.
(a) Describe how the student could determine the total thermal energy transferred to the rock during the first 160 s of heating using only measurements already mentioned.
(b) Explain why restricting the analysis to the first 160 s rather than the entire heating period is likely to reduce the uncertainty in the calculated specific heat capacity.
(c) Identify two significant sources of systematic error that could arise in this experiment and state for each whether it would cause the calculated specific heat capacity to be greater than, less than, or equal to the true value. Justify each choice.