1 / 22

Modern Physics (PC300)

Modern Physics (PC300). Class #8: Quantum Mechanics Born. Test Assessment. Photoelectric Effect. -. +. Photoelectric Effect: Intensity. Makes Sense: more photons - more electrons. Photoelectric Effect: Frequency. 1902: Lenard -. Maximum KE does not depend on intensity.

bmcelroy
Download Presentation

Modern Physics (PC300)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Modern Physics(PC300) Class #8: Quantum Mechanics Born

  2. Test Assessment

  3. Photoelectric Effect - +

  4. Photoelectric Effect: Intensity Makes Sense: more photons - more electrons

  5. Photoelectric Effect: Frequency 1902: Lenard - Maximum KE does not depend on intensity 1905 Lenard - Nobel Prize

  6. 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

  7. Photoelectric Effect: Work Functions (Kmax)

  8. Various Work Functions http://www.youtube.com/watch?v=m55kgyApYrY 1923 Millikan - Nobel Prize Why do different metals have different work functions?

  9. 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.

  10. Sim #4: Photoelectric Effect P-Drive\White\Modern Physics\Programs\Petutor\CTWINX Click on Photo15.ctb then hit OK

  11. Lab 6 – Photoelectric Effect

  12. X Ray Production 1901 Roentgen - Nobel Prize

  13. EM Spectrum: X-Rays (Duane-Hunt Rule)

  14. 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

  15. 1897 - J.J.Thompson 1906 - Nobel Prize

  16. X Ray Production

  17. Measuring charge/mass (e/m) Electron beam Cathode Ray Cathode Ray Tube Derive in lab

  18. Lab ? - e/m setup

  19. 1909 - Robert Millikan Precise Measurement of e Oil Drop Experiment

More Related