|Plank's Constant|| Main project page|
SJK Incomplete Feedback Notice
SJK 15:34, 17 December 2008 (EST)
Since the development of quantum mechanics in the early 20th century, the accurate determination of Plank's constant has been extremely important for accurate measurements. In experiment 1 (The Photon Theory of Light) we are going to demonstrate how the energy of electrons ejected when hit by photons only depends on frequency and not on intensity as predicted by the classical theories. In the second part of the experiment we will measure the constant of proportionality that is related to the kinetic energy of the electrons and the work function of the metal.
Partner: Manuel Franco Jr.
Results and Analysis
Even though we are going to take some more data, I think it is convenient to do some analysis now so when the new data comes in, we can just plug in.
Experiment #1 (The Photon Theory of Light)
Analysis for part #1 Image:Plank's Contant Part 1-1.xls
Green Line with Green Filter
Yellow Line with Yellow Filter
Experiment #2 Determination of h.
Actual Plank constant:(4.13)E-15 eV*s
Measured h:(3.72±0.16)E-15 eV*s
Actual work constant:1.36(8) eV
Percent Error:22.05%SJK 15:31, 17 December 2008 (EST)
I actually was a bit surprised by these results. I did not expect them to be close to the actual values, since the voltmeter went a bit crazy on us after a couple of measurments reducing the voltage previously displayed. Of course voltmeters do not go crazy, so there must have some reason as to why the voltage started to decrease. Maybe some charge got trapped? I not quite sure. But we decided to carry on and make the measurments anyway.
I used Ariannas Excel analysis to guide me through my analysis.