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Spring 2011
PHYS 172: Modern Mechanics
Lecture 22 – L quantization, Gyroscope
Read 11.1011.11
EXAM 3 is next week
Time: 8:0010:00 pm Wed Apr 13th
Place: Elliott Hall
Material: lectures 1522 and respective HWs
Problems: multiple choice, 14 questions (70 points)
writeup part, hand graded (30 points)
Equation sheet
:
provided
Practice exam: will be posted
Note: no lecture on April 14th
Angular momentum quantization
Elementary particles may behave as if they have rotational angular momentum
Electron may have translational
(around nucleus) and rotational
angular momenta
Angular momentum is quantized
Angular momentum quantum =
34
1.05
10
J s
2
h
π

=
=
×
Whenever you measure a vector component of angular momentum
you get either halfinteger of integer multiple of
&
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View Full DocumentThe Bohr model of the hydrogen atom
Niels Bohr
18851962
1913: electron can only take orbits
where its translational angular
momentum is integer multiple of
,
trans C
L
r
p
N
=
×
=
±
±
±
r
±
p
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 Spring '08
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 mechanics

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