physics lab report
Physics 102 Fall 2020
Adiabatic Compression Lab Project
The three tables below show the results of imaginary experiments done on three different ideal gases. One mole of each of the gases were adiabatically-compressed, leading to an increase in pressure and temperature, as seen in the tables. Your project is to determine what gases these are. You will need to make PV diagrams for each of the data sets, and determine the adiabatic constant, γ, for each experiment (I would suggest making plots of the logarithms of the pressure and volume - why?). Once you’ve determined the constants for each, you can use that constant to identify the gas.
Table 1: Unknown Gas Number 1 Data
Pressure (Pascals) Volume (m3) Temperature (Kelvin)
101300 0.024036 293.0020217 121560 0.021507797 314.6194726 141820 0.019578288 334.1266952 162080 0.018047364 351.9996072 182340 0.016796671 368.5565542 202600 0.015751514 384.0260811 222860 0.014862192 398.5785872 243120 0.01409422 412.3449869 263380 0.013422847 425.4283418 283640 0.012829799 437.9114446 303900 0.01230126 449.8619491
Table 2: Unknown Gas Number 2 Data
Pressure (Pascals) Volume (m3) Temperature (Kelvin)
101300 0.024036 293.0020217 121560 0.020968486 306.7303444 141820 0.018689892 318.9651547 162080 0.016917228 329.9572047 182340 0.015493719 339.9668835 202600 0.014322153 349.1778798 222860 0.013338846 357.7250435 243120 0.012500225 365.7105487 263380 0.011775408 373.2138254 283640 0.011141856 380.2979517 303900 0.010582711 387.0139284
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Table 3: Unknown Gas Number 3 Data
Pressure (Pascals) Volume (m3) Temperature (Kelvin)
101300 0.024036 293.0020217 121560 0.020922533 306.0581308 141820 0.018599867 317.4287739 162080 0.016797366 327.6193744 182340 0.015353007 336.8793358 202600 0.014166549 345.3842113 222860 0.013172451 353.2626286 243120 0.012325949 360.6118778 263380 0.011595364 367.507473 283640 0.010957613 374.0092966 303900 0.010395449 380.1657005
Your report should include various graphs, calculations and derivations, and your final answers should be in the form of a table, something like this (you can adjust this however you like, but you get the idea):
Table 4: Determination of the Unknown Gases
Unknown Gas Number Adiabatic Constant (γ) Gas
1 γ1 Stuff 1 2 γ2 Stuff 2 3 γ3 Stuff 3
The rest of this material is just copied from the previous lab, but I’ll always include it, because it’s important!
Once again - the point of this project isn’t to determine the coefficients(that’s too easy!) - but rather to get you used to doing a little research on something, and learning to write it up in a professional way. You’ll be graded on the effort that you put into the writeup, and the quality of the writeup, itself (I assume that you actually get the correct coefficients and gases!). Some of the things that I am looking for:
• Did you follow the correct format for the formal lab write up? Are all the group members listed (alphabetically)? Did you write in complete sentences, with good grammar? Did you write things in paragraphs, instead of making lists, and so on? In other words, does the write up look professional - would it be something that you would proudly submit for publication in a real journal?
• Did you only write things that you can understand, and write at a level at which any classmate could understand? It’s tempting to include scary-looking equations in your
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paper because they look impressive - and you can! However, if you’re including these scary equations, be sure that you understand them, and can explain them!
• When including equations and formulae, did you define your variables? Don’t display equations without telling the reader what the variables are! Also, are the important equations numbered? Do the equations look nice on the page (as they would look in a textbook, or when you’re writing them down), or are they messily just stuck there (i.e., do you write 1
2 at2, or 1/2 at∧2 - see how much better one looks than the other?)?
• Did you cite your sources, and list them in the references section? Were you sure to not simply copy and paste stuff from the internet (that’s plagiarism, and gets you kicked out of science!)?
• Did you actually discuss things, instead of just showing a page of calculations? Imagine that you’re giving a lecture on this stuff, and type that up! Look at real papers, and how much writing there is, compared to the amount of math!
This list of stuff isn’t just for this write-up, of course - it applies to all the labs that we’re performing, as well as to your research paper! The whole point of all this is to learn to write technical documents, which is much more important to your future careers than any particular lab that we’re going to do!
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