Heat Transfer as Energy Exchange

Purpose:   The purpose of this experiment is to observe the behavior of heat transfer. Through practical experimentation, our group is able to make reasonable hypothesis' about the occurrence of heat transfer. With tools that will allow us to measure variable we need, our group can justify or alter any presumptions made.

Fahrenheit vs. Celsius

We started by examining the relationship between Fahrenheit and Celsius. Values at boiling and freezing temperatures were looked at and these values were used to find temperature in Kevin. With the numerous values, we were able to determine our uncertainty through standard deviation.

Equilibrium Temperature

Using the given values, our group was able to calculate the final temperature, or the temperature at which the system is at equilibrium. We used theoretical equations of heat and set up the equation to describe an environment where no heat escapes.

Finding Specific Heat of an Aluminum Can

Using the measured values, we calculated the specific heat capacity of an aluminum can using our heat equations and the theory of energy exchange. We found that our experimental values were off a bit and composed a list of possible reasons why our calculations were off, in red, on our board.

Uncertainty of Specific Heat of Can

Graph Representation of Heat Transfer

Once the cold can was placed in the cup of hot water, a transfer of heat occurs. This is a graphical representation of both objects reaching thermal equilibrium. Our graph shows that the cup of hot water dramatically dropped in temperature while the cold can barely rose in temperature.

Cooling Rate

As a group, we created a list of variables that may effect cooling.

Heat Through an Object

In red, we created a list of variables that could effect the rate at which heat transfers. An equation for the transfer of heat is displayed in the top right corner in blue.

Heat Flow Through Copper and Aluminum

Here, we calculated the change in temperature using heat flow through the copper and the aluminum. We determined the heat flow by determining the total resistance factor of the two metals.

Graphical Representation of Heat Transfer

Heat vs. Temperature in Celsius showed to have a linear slope.

Making Sense of Our Graph

We were able to find the specific heat capacity by examining the linear portion of our graph. This linear portion resembles one of our fundamental heat equations Q=mc∆T, where mc is our slope variable.

Thermal Equilibrium

In an example of thermal equilibrium, we found that two cups of water, at roughly the same mass but opposite temperatures, came to the equilibrium temperature at nearly the same rate.

Conclusion:   We confirmed that the transfer of heat is dependent on temperature change, the masses that transfer heat, and the capacity at which they transfer heat. Using a similar principle, we were, also, able to determine the heat flow between two metals and found that the flow was proportional to the area at which it flows through and falls over the resistance of the flow due to the material. Various of other examples were done to confirm the theory of heat flow, such as inserting the can into the cup of water and examining the rate at which the system reaches thermal equilibrium. We found, in that example, that the aluminum between the two objects slows the rate at which heat transfers into the can, acting as an insulator or the water inside.