2130 HW 1
Due: Fri 1/24 noon. Turn it by putting it in the box labeled 2130 at the entrance to the helproom
(G2B90).
1. A big cannon shoots cannonballs the size of watermelons with an initial velocity of 132
Phys. 2130 HW02
Due: Friday 1/31 noon. Turn it by putting it in the box labeled 2130 at the entrance to
the helproom (G2B90).
1. (5pts. For both correct answers, otherwise 0pts.) Einsteins relativity
principles:
Physics 2130, HW 11
Due Mon. Apr. 21
1) An electron has a total energy as shown by the blue dashed line and a potential energy curve as shown by the
red line.
a) In which regions (1-8), would you expect the solutions to the Schrodinger equation, (x), to b
Announcements
Reading for Monday: 5.1 5.5
Today:
Back to our discussion about Photons!
All these fifty years of conscious brooding have brought me no nearer to the answer to the question, 'What are light quanta?' Nowadays every Tom, Dick and Harry thinks
Announcements
Reading for Wednesday: Review Ch. 4 Online questionnaire due next Wednesday (see assignment section on the web)
Exam 1
Last class we did the PE effect
and we found this V-I curve
Current 0 reverse V, no electrons flow. Looks kind off what
Phys 2130, HW 10 Due Fri Apr. 11
1. 5 pts. What is the smallest possible energy (in femto-eV (10-15) the ground state for an electron
in a 0.001 m (1 mm) wire? You may assume the wire acts as an infinite square well.
_
For the next 9 questions, consider t
PHYS 2130, HW6. Due date: Fri, Feb. 28 at noon in G2B90.
1. You illuminate a metal plate with light, which has the wavelength of 300nm. The ejected
photoelectrons have the velocity of 0.002c. a) 5pts. What is this
Phys 2130 HW 8 Due Fri Mar. 21
1. (5 points) Describe the limitations of the Bohr model. Which of these limitations does
the deBroglie wave model address and why?
2. (5 points) Suppose you have an electron with a kinetic energy of 4.5eV and a photon
with
Phys. 2130 HW04
Problems 1-4 are relevant for the exam. They are due: Wed. 2/12 noon. Turn it by putting it in the
box labeled 2130 at the entrance to the helproom (G2B90).
Problems 5-10 due Wed. 2/19 noon (
Phys 2130 HW 9 Due Fri. Apr. 4
1.a. 5 pts. Weve been using a bunch of new terms and symbols, including:
1.
2.
3.
4.
5.
,
|2,
*,
the wave function, and
the probability density.
Explain the relationship between these terms and symbols. Which could you infer
Q1
Photons
Interested in Teaching?
Become a Learning Assistant!
Get more info about the LA program: When: Wednesday, February 24th at 6pm. Where: UMC RM 235 RSVP: By February 19th to Olivia Holzman (olivia.holzman@colorado.edu)
The frequency of a beam of
Announcements:
Reading for Wednesday: 11.9 & 11.10 Exam 2 is next week (Tue. March 9th, 7:309:15pm) Topics: TZD, Chapters 1-5, 11.9, 11.10 Practice exam is posted on CUlearn. (Disclaimer: The exam next week will not be the same as the one posted.)
Energy
An single electron bashes into an atom in a discharge lamp
- 10 V + -2 eV -3 eV -6 eV -10eV If atom fixed at this point in tube, list all the possible photon energies (colors) that you might see? A. 1eV, 2eV, 3eV, 4eV, 7eV, 8eV B. 4eV, 7eV, 8eV C. 1eV, 3e
Reading for Friday: 5.8 5.10 Interested in becoming an LA, or simply simply interested in free food? Go to UMC, Room 235 tonight at 6pm.
increasing energy
Announcements
What do the vertical arrows represent?
allowed energies
ground state a. arrows on rig
Announcements
Reading for Wednesday: 5.6 5.7
Which slit did this photon go through? a. left b. right c. both d. neither e. either left or right we just cannot know which one
Which slit did this photon go through?
If one slit: Get single slit pattern (i.e
Announcements:
Reading for Friday: 6.1 6.3 Exam 2 is next week (Tue. March 9th, 7:309:15pm). Topics: TZD, Chapters 1-5, 11.9, 11.10 11.10 Office hours: Today 1 3pm
Today: LASERs!
Q1
Whats so special about LASER light?
A) It doesn't diffract when it goes t
Announcements
You just woke up inside a boat with no windows.
The boat is on the surface of a perfectly still lake.
How can you determine if the boat is moving at a
constant speed or if it is standing still relative to
the shore?
Reading for Friday: TZD
Galilean velocity transformation
u
x
. -3
-2
-1
0
1
2
. -3
-2
-1
v
3 .
x
0
1
2
3 .
If an object has velocity u in frame S (note:
velocities have a direction!), and if frame S is moving
with velocity v along the positive x-axes of frame S,
then the positio
Announcements
What we found so far:
Reading for Wednesday: Review 1.9-1.12
and 1.13
Simultaneity of two events depends on the choice of
the reference frame
HW2 due Wednesday noon.
L
R
v
Joel
-3 -2 -1
0
1
2
3.
Tom
G1B30
G1B20
Phys help room
(G2B90)
Joel
The famous Michelson-Morley
Experiment tests if the speed of
light in all inertial frames
Announcements
Reading for Wednesday: TZD 1.10 1.11
Homework #2 Will be posted this afternoon
A is the same in all directions.
Register your clicker! (myCUinfo)
B
2130 MODERN PHYSICS 3 FOR ENGINEERS
KYLE MCELROY
Today
Relativity
Quantum mechanics
So called Modern physics
Day 1:
Why are we here?
Whats this class about ?
What do we need to do ? How do we plan on doing it ?
Introduction
Why the class is as it is
Struc
1
2
Announcements
Joel
Two firecrackers sitting on the ground explode. Joel is
standing twice as far from firecracker 1 as from
firecracker 2. He sees the explosions at the same
time. Which firecracker exploded first in Joels
reference frame?
A. Both expl
Todays class
Announcements
Reading for Friday: 2.4 - 2.6
HW 4 Assigned today. Due next Wed. noon.
Some of the topics on this will be on the exam!
Chapter 2:
First Midterm is on the 16th. Will cover relativity
(Practice questions will be put on CULearn
The exam last night was
Part 2: Quantum* Mechanics
a) Way too easy
b) Too easy
c) Just right
d) Too hard
e) Way too hard
f) Where is the f) button.
Courtesy of IBM
*We say something is quantized if it can occur only in certain discrete amounts.
Part 2 of
Electromagnetic waves carry energy
Emax
Electromagnetic waves carry energy
Emax=peak amplitude
X #1
c
Emax
X
X #2
E1max=E2max>E3max
f1 = f3 < f2
X #3
Which barrel will heat up the fastest?
a. 2>1>3
b. 1>2>3
c. 1=2>3
2
d. 1=3>2
e. 2>1=3 Intensity = power/a
Today (and next class):
Announcements
Light is a wave! Or is it? (also some E&M refresher)
Reading for Monday: 4.3 4.4
HW5 Assigned Wednesday.
Participation scores up today
Still updating CULearn.
Midterm average 77 14
How do you generate light (elec
Announcements
Todays class
Reading for Wednesday: finish chapter 1,
(1.14).
A little more on evidence
for time dilation.
Length contraction
Lorentz transformation
HW3 assigned today due Wednesday noon.
CULearn website is up. Homework solutions
will
Today: Review of SR
Exam1: Tomorrow, 7:30-9:00pm, DUANE G1B20
IN THIS ROOM! (unless I emailed you
otherwise)
You can bring 1 paper (Letter format) written on one
side with whatever you think might help you during
the exam. But you cannot bring the textboo
Announcements
Reading for Review chapters 1 and 2
A proton (mass 1.6e-27 kg) is travelling at 0.99 c. How
much Kinetic energy does it have?
HW 4 Due Wed. noon. Some of the topics on
this will be on the exam! Dont be late.
K = (-1)mc2
a) 6e-11 Joules
Fi