modern physics 2008 trimester 3

course expectations            syllabus
   
       
 
Monday,
May 26
Tuesday,
May 27
Wednesday,
May 28
Thursday,
May 29
Friday,
May 30
class
 none
Memorial Day
 
 
 
 Modern Physics final exam
what we'll do
in class





reading
(always done
before class)
 
15(8)

what does the 8-fold way tell us?
15(9)

what is the circumstantial evidence for quarks?

what is the direct evidence?
15(10)

why is the circumstantial evidence for color?

is there direct evidence?
 
what to prepare for class


can you find the triangle hidden in the meson octet?

the bowling-pin decuplet?

what shapes will these diagrams if we add a fourth quark?  a fifth?


written
homework
(by 5 pm)

 

 bubble chamber solution due
 
lab
 
if your lab book on E2
was "removed"  I need you to re-turn-in questions 15, 16, 17
from
lab E2
(on paper is ok)
 
 
 
other
 

 
 


 
 
Monday,
May 19
Tuesday,
May 20
Wednesday,
May 21
Thursday,
May 22
Friday,
May 23
class
 shortened
 
 
 
 
what we'll do
in class

measure and record on bubble chamber sheet all your h's and c's

i will check in class, so make sure you bring this to class; it counts for a grade

quiz on all nuclear physics
(chapters 13-14)
and conservation laws
(part of chapter 15)

bring notes, textbook, handouts, old homework, old labs

bring cyclotron handout


finish discussion of particle accelerators

reading
(always done
before class)
review 15(1,3,5)

new: 15(2,4)

handout on Particle Accelerators (pick up from the black box), up through the end of cyclotrons 
we'll try this again:

 
handout on Particle Accelerators (pick up from the black box), up through the end of cyclotrons

check claims made in the article; jot down questions if you don't understand a claim
we'll try this again:

 
handout on Particle Accelerators (pick up from the black box), up through the end of cyclotrons

check claims made in the article; jot down questions if you don't understand a claim

 
in-class
presentation
see below

do you have one ready??


written
homework
(by 5 pm)


do these on the back of your bubble chamber sheet

 1) derive, on your own, using simple geometry, the relationship
between r, h, and c

2) starting with a magnetic force diagram and net force equation, show that for a particle with electric charge q in a magnetic field B

p = qBr

where p is the relativistic momentum and r is the radius of the circle in which it moves

3) Show that

pc (in Gev) = k r(cm)

and find the numerical value of k in Gev/cm for the magnetic field given on the page

people in Singapore, can you email me this?




1) consider the electron to be a sphere of charge

find the
equatorial rotational  speed if it has a spin angular momentum of "1/2" h-bar

we know that the size of the electron is
< 10-18 m



2) calculate all the r's and pc's for your particles on the bubble chamber sheet
AND
measure all relevant angles
(on your bubble chamber paper of course)

you might also want to calculate the E's for the particles you can identify






















 
 
lab
 
 
 make a decision about whether you personally want me to tell you
the identities of
alpha, beta, Q, Z
 
 
other
 

 
 physics of cyclotrons


 
 
Monday,
May 11
Tuesday,
May 12
Wednesday,
May 13
Thursday,
May 14
Friday,
May 15
class

 
 
 
 
 
what we'll do
in class
finish nuclear fission:

leftover questions:

what are the three main ways we can separate one isotope of U from another?  be able to explain the physics of how these methods work!

critical mass.... why do we need one? why can't any mass do it?

why is cadmium used for control rods?

left-over questions on fission:

where did the rest of the energy (the book said 200 Mev were released per fission).... the 3 examples presented in class were nowhere near 200 Mev!!

where is the rest of me?

we already have one method of separating the 2 uranium isotopes:
1) diffusion
(U235 will move faster than U238 if they are in a gas at the same temperature)

we need 2 more methods!!

also the control rod question from yesterday

talk about  fusion:

questions to know the answer to before coming to class:

1) why is fusion more difficult to initiate than fission?

how do we humans solve  that problem?
(how does the sun solve it?)

2) why is fusion more difficult to sustain than fusion?

how do we address that problem?

3) how can we estimate the temperature required for fusion?




bring your particle books
(that you ordered from the Particle Data Group)
to class



questions to know the answer to before coming to class:

1) why is fusion more difficult to initiate than fission?

how do we humans solve  that problem?
(how does the sun solve it?)

2) why is fusion more difficult to sustain than fusion?

how do we address that problem?

3) how can we estimate the temperature required for fusion?


bring your particle books
(that you ordered from the Particle Data Group)
to class

reading
(always done
before class)
have you finished reading 14(5)?

also, 14(3) and the end of 14(2)
14(6) 
15(1,2 and 3) should be a brief review

you've already read 15(4)

15(5) is new
 
 
in-class
presentation
since no one did one last week, EVERYONE needs to bring this to class:

energy released in one U235 fission done and brought to class
(you have a choice of three different reactions given in the book)

or make up your own!

I may collect it in class

Chart of the Nuclides





written
homework
(by 5 pm)

14(22, 24)
 

14(27) and the problem that we started in class:  prove that -- in a collision of an initially moving particle n with
an initially stationary particle p -- the maximum KE is transfered when the two particles have the same mass
(hint: you will need to write the KE transferred in  terms of only
the masses of the two particles and the initial speed of particle n)
 
lab
 
E3 radioactivity lab due
(presumably you picked up your top quark lab books saturday or sunday)
 
 
 
other
 

 
 


 
 
Monday,
May 5
Tuesday,
May 6
Wednesday,
May 7
Thursday,
May 8
Friday,
May 9
class
 
 
 
 
 
what we'll do
in class

you will work on radioactivity problems
(TO BE HANDED IN !):

from the canary sheet:

1) front side, left column:
problem 43 on the wooly mammoth

any two of the following:

2) back side, top left, first problem on the moon rock
and K-40

3) back side, top left, second problem on camping lanterns and thorium-232

4) front side, right column,
problem 47 on the shroud of turin


as we learned yesterday,
start with what the problem tells you (translate the english into an equation);
perhaps add a conservation law (as we did yesterday in the Rb/Sr problem);
use the radioactivity laws to solve for the unknown

you can check periodically with other students that you are on the right track....
but remember that does not include looking at someone else's paper



finish our discussion of nuclear fission


see questions below
reading
(always done
before class)
 13(5)

know the 2 basic radioactivity equations

know how to determine ages from radioacticity
 
 
 14(1) and 14(4, first 2 pages)
finish 14(4) and continue through page 516

questions to know the answer to for class:

does a single uranium fission produce the kinetic energy announced in the book?
(a nice show/tell here)

why does the uranium fuel have to be enriched in some reactors?

why does a U-235 require a slow neutron for fission?
(you learned this in your first physics course!)

how do you slow neutrons down?
(you learned this in your first physics course!)


in-class
presentation
time fro round 2 of show and tell


do you have one ready for today?

written
homework
(by 5 pm)
determine the KE released in an electron capture of O15

and in a
b+ decay of O15
 

 
13(58)

the whole problem!!!
not just the part we tried in class!!
lab
 
 
 
lab E3  on radioactive decay 
 do I have your top quark lab book?
I am grading that this evening!!

have you collected your data for lab E3??

we are taking down the radiation monitors today or monday!
other
 

 
 


 
 
Monday,
April 28
Tuesday,
April 29
Wednesday,
April 30
Thursday,
May 1
Friday,
May 2
class
 
 
 
 
 
what we'll do
in class


finish alpha decay and see how the KE's are apportioned between the alpha and the daughter nucleus
test on
chapters 1-2

reading
(always done
before class)
 
13(2) particularly mid p.475 - 476 on how the nuclear force works 
the section of alpha decay, which begins on page 484 up to the middle paragraph on page 486
p. 487 - 490,
 about beta decay
p. 491 - 493, top,
gamma decay and decay series

how is beta+ decay different than beta- decay?
in-class
presentation

find momentum
(magnitude and direction) of the neutrino
if you didnt put up your results yesterday on the board, make sure that you have them for today for some partial credit


find mass of top quark

written
homework
(by 5 pm)

 
problems 8, 13
tan sheet
DUE BY NOON
 
 
lab
 
 
 
 
 top quark mass lab due today
other
 

 
 


modern physics pages for april 2008
modern physics pages for march 2008