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April 30 |
May 1 |
May 2 |
May 3 |
May 4 |
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| what
we'll do in class |
master
beta decay |
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(always done before class) |
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| in-class
presentation |
1
done in block C 0 done in block D (3 expected per week; the course is now more than 50% over; you should already have done 1) |
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homework (by 5 pm) |
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April 23 |
April 24 |
April 25 |
April 26 |
April 27 |
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"Fundamentals of Particles and Interactions" with you to class if you have one (block C and Astrophysics people do); block D, non-Astrophysics people will get one today in class |
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| what
we'll do in class |
quiz
on chapters 1 and 2 you will be able to use your notes (and returned homework) on today's quiz (to look up formulas for relativistic collisions, for example); so please bring those with you to class; please pick up all homework for the box or stray-paper envelope you will not be able to use the book |
talk
about binding energy: be prepared to 1) define binding energy in words 2) define binding energy in terms of an equation (and explain how equation 13.4 comes out of the conservation of energy principle) 3) understand the implications of the binding-energy curve: how does it tell us which nuclear reactions are exothermic and which endothermic? how does it explain why we have stars of hydrogen and nuclear power plants that use uranium rather than vice versa? 4) how the conservation of energy principle allows us to determine a limit on the size of the nucleus (mid-page 466) 5) block D only: the range of the weak force is 10-18 m... what can you therefore say about the exchange particle of the weak force? |
a lab on the mass of the top quark bring your E1 lab notebook to class for this lab questions you should be able to answer after you have done the reading: 1) what particles are colliding in this accelerator (the one that produced the top quark)? 2) how did we accelerate the particles to great speed? 3) what keeps the beam from spreading out and dispersing (beam dispersion would result in not many head-on collisions)? 4) why did they build the accelerator in a circle (rather than a line)? 5) what makes the particles go in a circle? 6) what's the signature of a top quark? (what would the experimenters have to see -- since we cant actually see a top quark -- to know that one was there)? |
leftovers from tuesday: 3) understand the implications of the binding-energy curve: how does it tell us which nuclear reactions are exothermic and which endothermic? how does it explain why we have stars of hydrogen and nuclear power plants that use uranium rather than vice versa? |
how the conservation of energy principle allows us to determine a limit on the size of the nucleus (mid-page 466) and so why did he get the wrong answer (10x too larger than the actual size) when he applied this principle? where did Rutherford get the alpha particles to do his scattering experiments? (well, he didnt do the experiments, of course, his grad student, Geiger, did, but it was Rutherford's idea) so why is the answer to his calculation of the size of the nucleus (based on measurements) too small compared to the "claimed" nuclear size? plus new questions from your reading: in alpha decay, which of the two products has more momentum? more kinetic energy? higher speed? ditto for beta decay? |
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(always done before class) |
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pp. 590 - 600, on how to find a top quark |
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bottom of p. 487 - bottom of p. 489 |
| in-class
presentation |
yes! |
top quark lab: bring your neutrino momentum magnitude and direction and the total energy of each jet/particle to class |
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homework (by 5 pm) |
rocket/earth homework will hopefully be graded by 9 pm |
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#3 and #12 |
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13(15) (just ONE of the nuclei given, your choice) BUT please start from scratch with conservation of energy does you result match the BE/nucleon graph? |
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what's the beam doing now? |
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April 16 |
April 17 |
April 18 |
April 19 |
April 20 |
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| what
we'll do in class |
an
explosion problem, wherein we conserve momentum and total energy |
lab E2 |
compare gravity, electric, and nuclear force basics |
flesh out more details on how forces are transmitted, how we know the size of nuclei, and what binding energy is |
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(always done before class) |
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chapter 13, section 1 up to (not including) nuclear stablility.... much of this should be a review (mostly from chemistry, some from physics); helpful for prelab chapter 15, section 5 on conservation laws, but this probably also requires the first 2 pages of section 15(4), up to, but not including "the solar neutrino mystery...." |
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hopefully in your first physics course, your teacher expected you to know the answers to the following for the gravity force and the electrostatic force (and maybe even the magnetic force).... your reading should have been sufficient to answer these same questions for the strong nuclear force: (I will ask you these tomorrow) what particles does the force act on? (or equivalently, what is the "charge" of the force?) how many "charges" are there? what are the rules for attraction and repulsion? what things does the magnitude of the force depend on? (and how does the strength depend on these things)? how does the strength of the force compare to the strengths of the other forces? |
section 13(2) on how forces are "transmitted": know what determines the range of the strong force (and the other forces too!) & what binding energy is, and how to calculate it & how they got the first equation on page 466 |
| in-class
presentation |
yes, today |
yes, today | |||
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homework (by 5 pm) |
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& prelab to E2 done in new lab book |
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(also remember to bring to class the ratio of the grav force to the electric force for a proton/electron in the H atom and the magnitude of the electric force between 2 protons in a helium nucleus) |
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