Thermal Expansion & Laten Heat Fusion (Update)

We started the class talking about thermal expansion. Mr. Mason demonstrated how an object would expand when heat is continuously applied to and object. We see thermal expansion every day just by looking at the ground. When building a bridge or a walkway, workers will leave space in between sections.

 

 

This was the prediction of what was going to happen to the rod when it expands. Since this is only a prediction we might be wrong, but through our keen minds we believe that we are right.

 

In the picture above we see how applying heat to one end of a rod will cause it to expand. Since we are not applying a extreme amount of heat it does not expand a noticeable amount to the human eye. To measure the expansion we marked off a meter of the rod and placed a rotary wheel that measures degrees rotated in rads. With that we will be able to find the final length of the bar. The temperature at the one end is 100 Celsius.

 

 



 

This is the equation that we used to measured the coefficient of thermal expansion of the bar. We figured out that the bar is steel. The major equation for this calculation is L=R(theta).

 

These were the steps that we were going to use to calculate the Latent heat of fusion. the specific heat, and the latent heat of vaporization. Well to be more precise these are the step to aware the data need to calculate those three values.

In the experirmnet we collected the temperature change in the cup. This was the physical representation of the problems that we have been doing in class. This would be a very good quiz problem. Nevertheless, the water boiled at 100 degrees Celcius. That allowed us to get accorrect data in the phase change of water. We let the water stay at 100 degrees for a while before we stopped the collection.

We had sure that we took the different masses of the cups, water, and ice added in this experiment since we are going to do the cacluations of the specific heat of water. The more information that we had is welcomed. This was a picture of our lab set up. Some water did spill during the process so that will mess up the calculations.

 

 

In these calculations above we see how to calculate for phase change in water. First we have to see if there is enough energy to change the solid into a liquid. We do this by finding the amount of Q needed for the ice to reach zero degrees. Then we check the amount of energy needed to change all the ice into water. If that is not enough we know that the system stays at zero. If it is enough we can use another calculation's with the left over energy to see what is the final temperature. We take positive with some values because energy is leaving.