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Explore the intricacies of the photoelectric effect, born test assessment, and the relationship between light intensity and electron emission. Understand key concepts in quantum mechanics and the historical significance of Einstein's work. Engage in simulations and experiments to grasp the core principles of modern physics.
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Modern Physics(PC300) Class #8: Quantum Mechanics Born
Photoelectric Effect: Intensity Makes Sense: more photons - more electrons
Photoelectric Effect: Frequency 1902: Lenard - Maximum KE does not depend on intensity 1905 Lenard - Nobel Prize
1905: Photoelectric Effect: Solution Classical electromagnetic theory has problems explaining the independence of Kmax and light intensity, the linear dependence of Kmax on light frequency and the instantaneous (10-9s) response of the photocurrent. Einstein - Light composed of irreducible "grains" - quanta (energy packets). 1921 Einstein - Nobel Prize 1905 What a year for Einstein http://www.aip.org/history/einstein/chron-1905.htm
Various Work Functions http://www.youtube.com/watch?v=m55kgyApYrY 1923 Millikan - Nobel Prize Why do different metals have different work functions?
Problem Set for Wednesday • To answer the first two questions you will first need to do a Simulation. • Run the Photoelectric Effect program by following the steps below. • P:\Academic\White\PC301 Modern Physics 2013\Programs\Photoelectric\Photoelectric_en • Take data to answer the following question. • 1. Using five different wavelengths striking Sodium, calculate the ratio h/e. (Hint, make a graph in Excel of the Stopping Potential vs. frequency. Include this graph, with a trendline, in your homework solution. And remember, that all graphs need labels, a title, and a short caption…) • 2. Find the Workfunction for each of the six elements (most of which are metals…including the unknown) used in the simulation. Make a simple chart of your findings. Write a few sentences that clearly describe what procedure you followed and how you arrived at these conclusions.
Sim #4: Photoelectric Effect P-Drive\White\Modern Physics\Programs\Petutor\CTWINX Click on Photo15.ctb then hit OK
X Ray Production 1901 Roentgen - Nobel Prize
EM Spectrum: X-Rays (Duane-Hunt Rule)
Quantum Homework Questions Some Simulation Questions and an Electron Gun question Also… Thornton and Rex! "Yeah, well I got mine first Due Wed normal time
1897 - J.J.Thompson 1906 - Nobel Prize
Measuring charge/mass (e/m) Electron beam Cathode Ray Cathode Ray Tube Derive in lab
1909 - Robert Millikan Precise Measurement of e Oil Drop Experiment