In this lab of chapter 17 was in which introduced the thermal expansion of materials as well being able to apply the formula. A rod was placed on a clamp to a rotary motion sensor to the other end, with a connection to a device that produced steam to one end. It was proven by a demo that when heated to a certain temperature, the material expands causing in this case for the rod to expand and move the rotary sensor. As a result to the angular displacement we had to find the relationship between the angle to the coefficient of the expansion formula to verify the relationship.
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| This is the set up for the experiment with the rod clamped to one side connected with the steam and the other to the rotary motion sensor to calculate the displacement and show the relationship with the coefficient of thermal expansion. |
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| This was our group's interpretation or work showing how the angle relates to linear expansion and what is needed, unknown variables, to solve to find the linear expansion by making the equation alpha=pi*diameter*angle change/initial length*temp change*360 degrees. |
The group's calculations of the coefficient showing that the uncertainty of the lab which was the diameter. As a result a propagation of error was calculated from the equation in order to find the right material of the rod to confirm the relationship between the two.
The second part of the lab was to heat a mix of ice and water to the boiling point of 100 degrees Celsius by using an immersion heater. Before the experiment was done the groups had to predict the graph of temp vs time and then compare it to the actual graph of the experiment. The latent of vaporization and fusion can also be found by using this experiment by using the time for the ice to melt with the water and reach temperature to 0 Celsius.
This a prediction of the graph temp vs time prior to the experiment to show what we think how the temperature will change by including a lag phase before it starts heating up and then staying constant again when it boils.
The actual graph after the experiment reveals a smoother transitions of temperature changes through the graph in which at the beginning showed no lag/constant line into a direct diagonal making our prediction a little off.
And the last parts on this lab was determining the latent heat of vaporization and latent heat of fusion which are involved with the phase changes of the water. We were to write a plan on how to find both of the values and we came up with almost doing the water heating experiment. We place a mixture of water and ice using temperature probe and an immersion heater to increase the change in temperature. We take the initial mass, temperature of the water and seeing the time it takes to melt the ice to find the latent heat of fusion. And for the latent heat of vaporization we did the same but without the ice and let the water reach 100 degrees Celsius where the water started to vaporize. Lastly we selected a specific time length to allow the water to vaporize and after take the final mass of the water to insert into our equation process in the image below to find the value of the vaporization.
f. The amount of minutes that we used to allow the water to vaporize was 200 seconds to use in calculation
g. And the amount steam that was released by the experiment which was the change in mass with the uncertainty of +/- .0001 Kg was the value of 0.028 Kg.
This is the calculations of the finding of the latent heat of vaporization, by using the plan to determine it. It also shows the uncertainty of the experiment that accounted for the error which included the mass change, the power of immersion heater and the time change to find a conclusion. We found that our value for vaporization was 1.708*10^6 J/Kg and compared it to the other groups and the specific heat of water is 4190 J/gC.
The experiment set up of the cup of water with the immersion heater along with the temperature probe to determine the latent heat of vaporization by stirring until is started boiling.
By using the excel program we were able to find the standard deviation of all the group's values for latent heat of vaporization and compare to one another to find the difference.
The value of the deviation was 858363.048 by using the average of all the numbers, as well as the sum plugged into the equation to find the uncertainty of our group's value. The values or variables that showed uncertainty was the mass +/- .0001 Kg, the power of the immersion heater +/- .05 W, and the time change which was /- .5 seconds.The reason why the values can be uncertain is because the transfer of the cup from the experiment to scale losing some mass in the steam causing an error, and the heater label says 300 W but in reality it isn't having an average of 290 W with +/- 10 Watts. As a result to those errors and calculations by our group and the other's calculations, our value of 1.708*10^6 J/kg is far off from the standard deviation which makes our value not valid according to standard deviation however is closer to the actual value of latent heat of vaporization which was 2256 J/Kg.
Pressure, Volume, and Temperature Lab
The second lab of day 2 was experiments to show the relationships between each of the following which are temperature, pressure and volume pertaining to the Ideal Gas Law. We experimented with a straw and water to show the relationship of pressure and volume while the other was with a syringe and pressure sensor to show that relationship.
This is the relationship we found to be with the pressure and volume to find that it is inversely proportional to each other and the room temperature staying at 24 degrees Celsius.
With the graph below by doing the experiment of increasing pressure to a volume with the syringe proved that the volume decreased revealing that they are inversely proportional to each other. P - 3288 J/ V in which the value of A is replaced by 3288 J(N/m). The purpose or physical meaning of the value A or slope is energy is the amount of energy required to decrease the volume by the addition of certain amount pressure, Boyle's Law.
The graph shows the inverse relationship between the pressure and volume from the experiment of adding pressure to a syringe. The slope of the graph was 3288 N/m.
The experiment set up of the pressure vs. temperature were the flash is placed in hot water and a syringe adding pressure to the experiment showing the direct proportional.
According to the graph shown below reveal that the relationship between pressure and temperature are directly proportional because when the temperature increases as a result the pressure also increases showing a linear relationship and shape in the graph. The physical meaning of the slope in this graph is the change of volume within a constant temperature and the amount of pressure needed to increase by one degree in temperature, Guy Issacs Law.
The actual graph from experiment showing the relationship is directly proportional to each other, so if one increases then the other increases as well. The slope was .2368 kPa/C.
Although upside down the picture shows the prediction of the graph before the experiment and shows the relationship between pressure vs. temperature to be directly proportional.
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