September 06, A B Which is which? What does Planck suggest? instead of resonantors being able to emit energy at any speed or energy?

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Madeline Gilbert
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Michelson - Morley Interferometer Relativity and similtineaity digital media downloads another external michelson-morley The Electron Volt? units? Derivation?

1 Michelson - Morley Interferometer Relativity and similtineaity digital media downloads another external michelson-morley The Electron Volt? units? Derivation? Michelson - Morley Experiment Time dilation Light Clock - Time dilation external link The electron volt is the same as what unit? explain Length Contraction Twin paradox illustration digital media downloads eδv = Pair Production and Annihilation Blackbody radiation Phet A B Which is which? Explain the process for each? What must be conserved in each? What does blackbody radiation mean? What happens when objects increase in temperature? Explain the equation for pair prod. hf min = 2m e c 2 If we measured the radiation emitted as temperature increased, what would it read? classical theory (wave) vs quantum (particle) Why m e and not m p? why 2? what does hf min represent Planck's hypothesis and constant What does Planck suggest? instead of resonantors being able to emit energy at any speed or energy? Ultraviolet catastrophe - theory and experiment contradict each other. The contradiction happens in the ultraviolet region (wavelength) Classical suggest as wavelength approaches zero energy should be infinite. Experiment shows as wavelength approaches zero energy approaches zero as well.

Planck's hypothesis and constant photoelectric effect video What is happening? Photoelectric effect review What is the photoelectric effect?

2 Planck's hypothesis and constant photoelectric effect video What is happening? Photoelectric effect review What is the photoelectric effect? explain Planck proposed submicroscopic charged oscillators that could only have discreet quantities of energy(quantized). ** not a broad range or spectrum of energies. Phet Simulation - discuss phet link The light emitted could be thought of individual packets of energy. "Particles" of light, each with a set amount of energy. E = nhf n is an integer h is Planck's constant = 6.63x10-34 Joule*seconds f is the frequency Problem If electrons cease being emitted from a metal when 500 nm light is incident upon the surface, then what is the minimum energy required to cause the photoelectric effect? in ev and Joules (Hint: Cutoff wavelength) How much kinetic energy will the electrons have? (if they have not been emitted from the surface?) The work funtion? in ev and in Joules What is the KE max of a photoelectron, produced by a 400 nm light shining on the same material as above? in ev and Joules What is the maximum speed of an electron with this kinetic energy? [ KE=1/2m e v 2 **this formula requires Joules] What voltage would be required to stop the electrons produced by the 400 nm light source? Try #13,14 and 11 and 12 in chapter 27 in order of increasing difficulty KE formula from academic mass of electron on the equation sheet in the constants

$Diffraction of x-rays Compton Effect or Compton Scattering **not done mathematically The shift in wavelength of the x-ray is due the the fact that the electron that was at rest is now?$ Producing an x-ray Debroglie waves What is happening in the picture? What happens to the energy of the electron? What is created? Where does it get it's energy from?

Producing an x-ray Debroglie waves What is happening in the picture? What happens to the energy of the electron? What is created? Where does it get it's energy from?

3 Diffraction of x-rays Compton Effect or Compton Scattering **not done mathematically The shift in wavelength of the x-ray is due the the fact that the electron that was at rest is now? explain Discuss the energy change for the electron? for the light particle (photon) Wavelength of the photon? Why it must be an x-ray? Producing an x-ray Debroglie waves What is happening in the picture? What happens to the energy of the electron? What is created? Where does it get it's energy from? does this contradict conservation of energy? Explain the equation Dual nature? What does the nature of light depend upon? explain Debroglie equation : p = h/λ (derivation on page 887) eδv = hf max = (hc)/λ max **electromagnetic waves have momentum even though they have no mass. Atomic Spectra Rutherford scattering Models of the atom? (Phet Sim.) Newton JJ Tomson Rutherford Bohr DeBroglie Schrodinger

4 absorption and emission Laser - Light Amplification by Stimulation of Radiation phet laser

5 Hydrogen atom E n = / n 2 ev Discuss Bohr model for hydrogen on page 908 try chapter 28 what we know about nuclear - supercouse (pitt) excellent Time it takes until half the substance is left. Conceptual Half Life - Conceptual Ex. If half life is 10 years, how much of a substance is left after 30 years? 3 half lives If it is not an equal amount of half lives t = time t 1/2 = half life N = amount of substance left N 0 = amount of substance equations 29.4b and 29.4c Nuclear Physics Simple Binding Energy - copyright schaum's guide ver9, page 402 What holds a nucleus together? What cause a nucleus to come apart? or decay? The total energy of the bound system (stable nucleus) is less than the combined energy of the separated nucleons. This can be thought of the energy required to break it apart. What is the binding energy of 12 C? Forces? Why is nuclear energy important to us? examples **As little as 4 kg of plutonium can be used as a nuclear weapon - baseball size : source federation of american scientists One atom of 12 C consists of 6 protons and 6 electrons, and 6 neutrons. The mass of the uncombined protons and electrons is the same as six 1 H (if we ignore the very small binding energy of each proton-electron pair). The component particles may thus be considered six 1 H atoms and six neutrons. A mass balance may be computed as follows. six 1 H atoms (protons)= 6 x u = u Mass of six neutrons = 6 x u = u Total mass of components = u Mass of 12 C atom = u Loss in mass on forming 12 C = u Binding energy = 931 MeV/u * u) = 92 MeV See Appendix B

6 Binding Energy The total energy of the bound system (stable nucleus) is less than the combined energy of the separated nucleons. This can be thought of the energy required to break it apart. Example problem 29.2 Deuterium - splits - (1proton + 1 neutron) How much energy must we add to split this atom apart? **use page 967 (table 29.4 for mass of proton and neutron) use Appendix B for Deuterium atom mass Before looking at the answer on page 943 A or mass number is the number of nucleons (protons and neutrons) Z or atomic number is the number of protons Practice page calculate Binding Energy of Helium -3 2 protons 3 nucleons - therefor their must be 1 neutron mass of helium -3 from Appendix B For practice * use page 967 or Appendix B for needed values chapeter Deuterium (sometimes D) * use page 967 Appendix B for needed values #10 Read through carefully, Example page 975 Using the Concept of Binding Energy to "get" energy Fission Fusion Radioactive Decay Fission Phet sim **The total mass of the products is less than the original mass of the heavy nucleus. Note - a great deal of energy is needed to get this started. Example page 975 Calculate the total energy released if 1.00 kg of U(235) undergoes fission. Q=208 MeV/event. How many kg of U(235) would be needed annually ; 4x10 20 J page 974 The curve peaks at A = 60, which means that nuclei further away from 60 are held less tightly and allows for both fission and fusion reactions (page 944, good to read)

7 Example page 975 Fission How many kg of U(235) would be needed annually ; 4x10 20 J Calculate the total energy released if 1.00 kg of U(235) undergoes fission. Q=208 MeV/event. How many kg of U(235) would be needed annually ; 4x10 20 J How many kg of U(235) would be needed annually ; 4x10 20 J Try this problem, after discussing watts and 40 percent efficient What do we do with the 40% efficient? Try problem 30.6 page 1004 Energy Total = # of Events * Energy per_event P*t = Energy Total Energy Total = # of Events * Energy per_event P*t = Energy Total

8 6.75x10 24 events/day * 1mol/6.02x10 23 events* 235 g/mol * 1k/1000g = 2.63 kg /day Each individual atom of a mol of material will have an event (fission) : therefore 6.02x10 23 can be molecules, events, atoms page 982 Example 30.3 Fusion *When two light nuclei combine to form a heavier nucleus, but because the final nucleus is less than the masses of the original nuclei, there is loss of mass and release of energy. Note - a great deal of energy is needed to get this started. H or D What happens when the sun runs out of fuel? What is the fuel? page 982 Example 30.3 Fusion *When two light nuclei combine to form a heavier nucleus, but because the final nucleus is less than the masses of the original nuclei, there is loss of mass and release of energy. Note - a great deal of energy is needed to get this started. Deuterium Exercise 30.3 page 982 Find the Energy released in the fusion of two helium-2 nuclei Extra practice , Fusion *When two light nuclei combine to form a heavier nucleus, but because the final nucleus is less than the masses of the original nuclei, there is loss of mass and release of energy. Note - a great deal of energy is needed to get this started. Decay Demo mysterious decay with labpro, alpha, beta, gamma - verify with paper, lead page 982 Example 30.3 Deuterium Exercise 30.3 page 982 Find the Energy released in the fusion of two helium-2 nuclei Extra practice , 30.10

9 Example 29.5 page 950 (todo) Alpha Decay Alpha Decay *In order for alpha emission to occur, the mass of the parent must be greater than the combined mass of the daughter and the alpha particle. (pg 969,Serway Faughn) as an example - write the equation and calculate binding energy involved Use table on 967 Thorium is missing from Appendix B Is this energy released or energy absorbed? Energy released and conservation of energy and momentum of Alpha Decay Alpha Decay Find the Energy given off - assume the beta particle has no mass and neglect the neutrino Find the max speed of the beta particle - if it gets all the energy Find the momentum of the beta particle and the copper, assume the nickel particle had no momentum originally - I will discuss as an example - write the equation and calculate extra energy (mass) involved Is this energy released or energy absorbed? in decay - an atom is split apart - fission - and releases energy The daughters have less mass than the parent find another alpha decay - todo Example 29.6 page 950 Beta Decay Phet sim *Appendix B Example 29.6 Beta Decay Try Exercise 29.6 page 951

10 Page 969 Find energy release and complete the equation Gamma Decay Radioactive Decay

11 Nuclear Chain Reactions September 06, 2011

Physics 3204 UNIT 3 Test Matter Energy Interface

Physics 3204 UNIT 3 Test Matter Energy Interface 2005 2006 Time: 60 minutes Total Value: 33 Marks Formulae and Constants v = f λ E = hf h f = E k + W 0 E = m c 2 p = h λ 1 A= A T 0 2 t 1 2 E k = ½ mv 2