User:Garrett E. McMath/Notebook/Junior Lab/2008/10/13/Summary

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This Lab was gave extremely accurate results contrary to my intuition. The difficulty in getting the data made me think that our results would be pretty bad. As you can see from the lab notebook our worst percent error from the accepted value was 1.4%. The only improvements I can thnk of would like the E/M ratio lab to use a camera to take a high resolution shot of the ring diameter to get more accurate readings. Given that all the geometric issues had already been resolved and could easily be factored in(though they did not affect the data a significant amount for the margins of error we were working with) their is not much else that could be done for the improvement of this data.

Inner Diameter
  • y=mx+b: m=1.32 with an uncertainty of .062 and b=.0023 with an uncertainty of .0014 (R^2=.895)
  • y=mx: m=1.47 with an uncertainty of .004 (R^2=.883)
Outer Diameter
  • y=mx+b: m=1.71 with an uncertainty of .019 and b=.0126 with an uncertainty of .00076 (R^2=.984)
  • y=mx: m=2.51 with an uncertainty of .0021 (R^2=.765)
SJK 17:32, 1 November 2008 (EDT)
17:32, 1 November 2008 (EDT)
it is not at all clear how you calculated the final values (your excel sheet does not show it). Also, you do not put uncertainty on your atomic spacings! You can do this by propagating the uncertainty of your slope (which as I noted in your notebook, you actually did not compute correctly with LINEST). Because spacing depends on inverse of slope, the relative uncertainty in spacing will be the same as relative uncertainty in slope (so it's pretty easy to propagate the uncertainty). Without uncertainty on your final answer, the %discrepancy from the accepted value isn't very meaningful!
Calculated Spacing of Carbon

Inner Diameter

  • Spacing from slope: .216nm (1.4% error from accepted value of .213nm)

Outer Diameter

  • Spacing from slope: .124nm (.81% error from accepted value of .123nm)