Day 2 Thermal Expansion and Latent Heats

Bended Rod

This is one of the experiments showing that different material has different thermal expansion.


Ball & Hole


This is another experiment showing different thermal expansion of materials. When the brass plate is heated up by the gas burner shown in the photograph, the hole will get bigger.


Question thinking

This is the thinking process about thermal expansion.

Linear Thermal Expansion experiment

To find out the coefficient of thermal expansion of the rod, we blew steam through the rod to make the temp. of the rod matches the temp. of the steam.

Temperature vs. time & angle vs. time

This graph shows the relationship between time and temperature and angular displacement during the experiment. 

Calculation and data

These pictures above show our calculation to find out α.

Heating up water

This is what we expect the graph will be when we heat up the water.

Heating up water (student version)

In order to find out the value of L in equation Q=mL, we put an immersion heater into a cup of water and wait to see how long it will take for the water to be boiled. 

Temp. vs. time

This graph shows the relationship between time and temperature, but the most important thing is we can get the information about how long it actually takes for the water to vaporize by weighting the mass of water.

Calculation & data

The calculation above shows how we can find out L in equation Q=mL.

Calculation work (excel)

This is the data of the whole class, and we are supposed to get the uncertainty of these data by using excel.

Uncertainty of data above

This picture shows the uncertainty of L by calculating the standard deviation.

Change of Phase problem

Adding heat problem

Derive of P=phg 

Pressure vs. volume

The blue line is the linear relationship that we expected between pressure and volume; however, the red line is the real relationship between pressure and volume.

Boyle's law experiment

Trapping certain amount of air in the syringe, the air will be compressed slowly to smaller and smaller amount by pushing in the plunger, and the gas is compressed so it can have enough time to come into thermal equilibrium in the room.

Pressure vs. volume

This graph shows the real relationship between pressure and volume in room temperature, which actually looks like a quadratic equation.

Derive of unit

Charles law experiment

To find out the relationship between pressure and temperature, we set up a experiment using a electronic pressure sensor, temperature sensor and computer interface to collect data from a cup of cold water and a cup of hot water.

Pressure vs. Temperature

The graph shows the linear relationship between pressure and temperature, which means the Pressure will increase when temperature increases when volume is held constant.

Summary of the day

What we did on day two of the class is to examine that different material has different thermal expansion, which can be affected by linear coefficient and volumetric coefficient.  We also observed the change of heat during different changing phases of water.  We did experiment on latent heat of vaporization to find out L in Q=mL, and we talked about the ideal gas law by doing experiment on Boyle's Law and Charles' Law.