phys 342 - lecture 1 notes - f12

8/11/2019 PHYS 342 - Lecture 1 Notes - F12

1/13

Lecture 1

Syllabus

Professor Wei Cui

Room 313 (PHYS)

Phone: 494-5395

Email: [email protected]

PHYS 342, Fall 2012

MWF 1:30-2:20 pm

Room 203 (PHYS)

Office Hours: by appointment

Textbook: Modern Physics by Tipler & Llewellyn (6thed)

Course Web Page:Blackboard Vista


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Lecture 1

Syllabus - Cont

d

Exams:Four in-class exams

Homework:

1. One problem set per week, due on Wednesdays

before the lecture2. Late homework will be penalized at -20% per day.

Quizzes:

Given at random times

Grades:

homework 30%quizzes 10%

exams 60%


3/13

Lecture 1

Classical vs. Modern

Newtonian relativity vs. Einsteins theory of relativity

Absulote time vs. relative time

Separation of space and time vs. unification of space andtime

Galilean transformation vs. Lorentz transformation

Newtonian mechanics vs. Quantum mechanics

Macroscopic vs. microscopic

Deterministic vs. probabilistic Continuum vs. discrete

Separation of particle and wave properties vs. duality

Intuitive vs. Counter-intuitive


4/13

Lecture 1

Inertial Frame of Reference

A frame of reference in which Newtons laws hold The first and second laws define inertia: a measure of

resistance to acceleration

Strictly speaking, it only exists in an empty space far,

far away from any mass, i.e., only in our minds.

To a very good approximation, distant stars define an

inertial frame of reference


5/13

Lecture 1

BlankSky


6/13

Lecture 1

Inertial Frame of Reference-Cont

d

A frame of reference that moves at a constantvelocity with respect to an inertial frame of

reference

Strictly speaking, no frames of reference attached to theearth can be viewed as an inertial frame of reference

Reference frames vs coordinate systems For a chosen reference frame, various coordinate

systems (e.g., Cartesian, spherical, cylindrical, ) canbe adopted for mathematical purposes.


7/13

Lecture 1

Inertial Frame vs. Non-inerital Frame


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Lecture 1

Galilean Transformation

tt

zz

yyvtxx

=!

=!

=!

"=!

zz

yy

xx

uu

uu

vuu

=!

=!

"=!

zz

yy

xx

aa

aa

aa

=!

=!

=!

vS

y

z

x

O

S

y

z

x

O

vt


9/13

Lecture 1

Galilean Invariance

Laws of mechanics are invariant under Galilean

transformation

Newtons laws

Conservation laws: energy, momentum, angular

momentum

Newtonian principle of relativity


10/13

Lecture 1

Application to Sound Waves

Doppler Shift: two cases

1. Source at rest, observer moving at a velocity

In the reference frame of the observer, the sound speedis vc+ , where c Is the speed of sound, assuming

the observer moves toward the source.

)1(/1 2

2

!!+!"+

=

+

=#c

v

c

vT

cv

T

vcT

$

Therefore, the period measured by the observer is


11/13

Lecture 1

Application to Sound Waves - Contd

2. Observer at rest, source moving at a velocity v

In the reference frame of the observer, the sound speed

is still c , since air does not move. On the other hand,

the wavelength of the sound is shortened by

)1(c

vT

c

vTT

c

vTT !=!=

!=" #

vT

vT

So, the period of the wave measured by the observer is


12/13

Lecture 1

Reading Assignments

Newtons Laws

Gravity

Hookes law

Conservation laws: energy, momentum, angular momentum

Waves and propagation of waves

Power and energy in waves

Reflection and refraction Coherence, interference, and diffraction

Doppler effects

Electricity and magnetism


13/13

Lecture 1

Reading Assignments Cont

d

Electromagnetic waves

Maxwells equations

Speed of light Properties of waves

Medium

Coherence

Interference conditions

Interference patterns from two reflective surfaces in awedgeconfiguration

Chapter 1, section 1-1

phys 342 - lecture 1 notes - f12

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