We put 0.2 kg of HOT water in one styrofoam cup, and connected that cup to anoth

Question

We put 0.2 kg of HOT water in one styrofoam cup, and connected that cup to another cup filled with 0.2 kg of COLD water. We connected them using an aluminum                     transfer bar. Using a thermometer in each cup, every two minutes, we recorded the temperature change in each cup.  I graphed the results and the lines do not cross- in fact, they are like mirror reflections of each other and eventually plateu.  Please help with questions!

How does the energy get from one calorimeter to the other?
What kind of heat transfer does this illustrate?
Why don

Explanation / Answer

1. The heat transfers always from hot to cold. specifically here it is from the hot calorimeter throught the aluminum transfer bar to the cold calorimeter.

2. This is known as conduction.

3. all depends on your data and how you graphed it. temperature (y) vs time (x) should give you a line going down and to the right (hot), that merges with another line moving right and up (cold) then if we assume these are perfect calorimetes and the aluminum bar is isolated from the outside air the lines should plateau.

4. the slope is greatest at the beginning, this is becuse heat transfer is exponential the closer two objects are to being the same temperature the slower the heat transfers the greater the difference the faster heat transfers. this also answers 5.

5. see answer 4.

6. q = -q, q=heat, -q is heat loss while +q is heat gain. You would have to look at your data but my assumption is that they are not the same. As I said before in question 3 we assume these are perfect calorimeters and that the aluminum transfer bar is only exchanging heat between the calorimeters. This however is not the case, heat is lost too the surroundings due to the calorimeters and also due to the aluminum bar being in contact with air (note that styrofoam is an insulator and aluminum is a conductor, IE conducters transfer heat more than insulators by large ammounts but insulaters still transfer heat hence the idea that the calorimeters are not perfect.) This is with my basic assumption of your setup in my head.

sorry for the typos i went fast if you have any questions just ask.

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