Thermal Expansion, Specific Heat, Pressure, and Latent Heat of Fusion and Vaporization (2nd Day)

Spring 2015

Professor Mason

February 26th

Heated Ring

This morning, we were given a ring to be heated, and we need to look at the hole whether it got smaller, bigger, or nothing happened. After we did the experiment, we found out that the hole of the ring got bigger after being heated. 

Thermal Expansion

The next thing we did was thermal expansion. In order to find the thermal expansion (alpha), we needed to find the arc length of the circle first as stated below.

After we found the L, which is [(diameter/2) * theta] ((theta is the angle)), next we use this converted L to the thermal expansion formula, which looked like the pictures above.

Bi-metal Strip
Another experiment that we did was bi-metal strip. We heated the strip to see how it would be looked like after we heated it. The strip looks like this:

At first, we had to predict how it would become if we heated the brass side and the invar side. The strip bent toward the invar side when we heated the brass side, as well as when we heated the invar side. This happened because the brass inductive. Next, after we heated it, the other experiment wanted us to put the strip in a bucket of ice. As a result, the strip bent toward the brass side. 

Latent Heat
There are two types of latent heat that we learned in class, and those are latent heat of fusion (Lf) and latent heat of vaporization (Lv). Those two types of latent heat can be found by looking it up on the internet. Those are used in a formula when a phase happens, such as melting and vaporizing.

 Errors
There are three types of error that we learned in this morning class, and those are: Systematic error, Random error, and Catastrophic error.

Pressure
Pressure or Power (P) has a formula, and it looks like P = rho g h. It involves density (rho), gravity (g), and height (h). Density (rho) is m/v, which m is mass and v is volume. These are the ones we did before.

The attached video below is our experiment before with manometer tube:

As we can see from the pictures and the videos above, we found out that the height (y) of the water changed. The one end of the straw has its water risen, while the other end has its water decreased. The change in level of water is directly proportional to pressure put into the system. After the experiment, we also found out that the change of the height is about 2.02 cm.
In addition, we found out that [rho * g * h] comes from [P=F/A] => [(rho * v * g)/ A] => [(rho*A*h*g)/A].

Heating Water Experiment
This experiment is about having a container that has a mixture of ice and water at 0 degree Celsius. Then, we started heating it at a constant rate and the water starts boiling after 5 minutes. We were supposed to predict on how the graph would look like, however, our predictions were way off. Therefore, this picture below is how the correct graph actually looks like: