Day 3 Gas Laws and Firs Law

What happen to the can

The can actually rapidly imploded when it reaches the surface of the water as we thought it would be.

Charles's Law I experiment

To find out the relationship between volume and temperature, we occupied the setup equipment above to give the flask a hot bath, a cold bath, and a room temperature bath, and we recorded three exact volume value of the syringe.

Volume vs. Temperature graph

This picture shows our calculation work of this experiment, and it also shows the linear relationship between volume and temperature under a stable/constant pressure.  The reason why the pressure of the air remains constant even when the volume of the air changes is because the heat is stored in the temperature - as the volume increases, the temperature increases.  The slope of the linear function, which is the coefficient, is 21.15 in our experiment.

Vacuum Chamber experiment

A balloon and a marshmallow were placed into a vacuum chamber.  When the pressured was reduced, the balloon and marshmallow expanded, and when the pressure was allowed back into the chamber, they both became smaller. However, the balloon stayed same size after the experiment while the marshmallow became smaller.

The heated syringe experiment

The flask was placed in hot water about 40° C, and this time we just held the plunger fixed instead of letting it go freely.  The flask and syringe were actually became hotter and hotter, which was caused by not letting them to expand the volume.  The heat went into the temperature and made the temperature increase.

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.

Day 1 Heat Flow and Specific Heat

Introduction of Temperature 
 
This is the graph to show the relationship between Fahrenheit and Celsius.

What affects the thermal conductivity

This picture shows that those four possible factor that affect the thermal conductivity: Surface area, difference of temp, thickness, and material. 

Experiment one: can apparatus

This picture shows the equipment that we used in the experiment: A can which contained hot water was put into a mug that contained cold water.  

Can apparatus 

This graph is created by logger pro, representing the relationship between two different temperature.  Two lines meet at the end, reaching an equilibrium.
Although they do not look like linear functions, we will only take certain piece of each line to find out the slope. 

Data and calculations:

Experiment two: heat transfer as energy exchange

We put an immersion heater into a cup of water (230 ml), marked down the room temperature which is 23.6 Celsius degree, measured the heater's wattage whose power is 288 watts, and used logger pro to record the data.

Temperature vs. heat

This graph shows a linear relationship between temperature and heat.  As temperature increases, heat increases.  Slope, whose physical meaning is heat capacity, is 0.873 of this function.  Generally we should get 1 as the slope, but since our mass it not equal to one so our slope is explainable.  We also found out that heat capacity is a mass-independent value since it will not change as we add or halve the mass of water.

Short summary of the day
What we did on the first lab is to introduce us the measurement of temperature, find out the factors determine the thermal conductivity, observe the relationship between heat and temperature, and get to know the property of heat capacity.