Heat capacity is a term used to describe the amount of heat / energy needed to be absorbed by substances in order for their temperature to change. This phenomenon is demonstrated often in water-based scenarios; for example, the Earth's oceans affect the temperatures in coastal cities, compared to cities in the Midwest. I wanted to explore heat transfer between different materials in water, and more generally, design an experiment surrounding thermodynamics in which I could figure out how to isolate and vary one of the variables that affects water temperature.

I designed this experiment in order to to explore laws of thermodynamics, and also to see & understand the physical effects of changing a variable (temperature) in a controlled system. I also wanted to manipulate temperature by introducing different materials into said system. By manipulating materials and seeing how they affect the temperature in a system, I hoped to indirectly investigate conductivity and heat latency in water.

My hypothesis was that metals would conduct heat the best, due to their low specific heat value and therefore easier ability to absorb heat.

The metals had the highest conductivity (copper and aluminum respectively). After came the plastics (nylon and then acrylic), and at the end was wood. After two minutes, nylon and copper had the highest recorded temperatures (18.7 °C and 18.0 °C, Fig. 3), while copper and aluminum had the highest change in temperature (11.1 °C and 7.6 °C, Fig. 4). The hot water temperature had an average of 62.2 °C, with an average deviation of 0.55 °C over fifteen measurements.

However, there was more variance in the cold water temperatures, with an average of 8.7 °C and an average deviation of 2.2 °C. The range in cold water temperatures can also be visible in Figure 1, given where all the measurements started at 0 seconds.

There were two variables that could have affected the thermodynamic process: water heat latency/specific heat, or the specific heats of the different materials used in this experiment. Since the liquid the materials were placed in stayed constant throughout the entire experiment, the independent variables were, specifically, the ability each material had to absorb heat. Water heat latency was consistent throughout this experiment; the energy needed to change the temperature of the system would have stayed constant. That amount of energy varied with each material depending on their heat conductivity.

Heat conductivity in order from highest to lowest is: copper (0.99 °C/cm²), aluminum (0.50 °C/cm²), nylon (0.24-0.3 °C/cm²), acrylic (0.17-0.19 °C/cm²), and oak (0.16 °C/cm²). This order is visible in the change in temperatures shown in Fig. 4; copper, which conducts heat the best, absorbed the most heat and therefore was able to transfer the most thermal energy to the cold water system.

Some sources of uncertainty present in this experiment were consistencies with maintaining temperature. I wasn't able to keep the temperature of the hot water identifiably constant while using the hot plate, and the amount of time the different materials stayed in the hot water was hard to gauge. In order to make sure the cube was a specific temperature, I took the cube out when the temperature of the heated water had been constant for a minute or so. Some changes I could make to this process could be using a more specific method of heating up water to an identifiable temperature, perhaps by boiling it or using a water bath at the price of additional time. I could also specifically measure the time the cube was in the heated water, as to keep the treatment constant across the experimental process.

I would like to go into further depth exploring thermodynamic rules, specifically by changing different variables such as volume or temperature to see their effects on a third variable, such as pressure. However, that would require more complex systems other than just vials of hot and cold water, but I could explore the relationships between those variables from both an experimental sense as well as a mathematical sense.