Tutorial: Tutorial examples will be posted at least a day before the tutorial so you can think about...

Preview:

Citation preview

Tutorial:

Tutorial examples will be posted at least a day before the tutorial so you can think about them to benefit most from the tutorial

Regular Quizzes (every 2-3 weeks, 15-20 min each) during tutorial

Relativity and QuantaPHYS 242Fall 2013

Lecture:

Lecture notes available ahead of time - READ and answer Pre-Lecture Quiz (Moodle)Tell me your questions via Moodle (or in class) – that’s what we’ll discuss

Assignments:

Will be posted Fridays, are due Monday, 10 days later, during the tutorial.

Exam:

Final exam in December (3 h)

Marking scheme:

Lecture Quizzes: 10 %Tutorial Quizzes: 15 %Assignments: 25 %Exam (final): 50 %

concepts, ideas, some derivations of fundamental formulae

application of the concepts, examples (help for assignments)

examples: experience in applying concepts to actual problems, feedback on learning success, practice for exam (assessment)

Motivator for learning, assessment

W. Rau

Books

Relativity and QuantaCustom version of: Serway, Moses, Moyer: Modern Physics ; Brooks/Cole -- Thomson Learning (available at Campus Book Store)

A.P. French: Special Relativity  W.W.Norton & Company Inc. New York

R. Eisberg, R. Resnick: QUANTUM PHYSICS of Atoms, Molecules, Solids, Nuclei and Particles John Wiley & Sons, New York, London, Sydney, Toronto

Course Web page:

http://www.physics.queensu.ca/~phys242/ :Lecture Notes, Assignments, Tutorial Questions, Solutions

Moodle: Pre-Lecture Quizzes, YOUR Questions, Grades

Relativity and QuantaPHYS 242Fall 2013

W. Rau

Newton’s laws:1. Inertia: Any object moves with constant velocity as long as no net force acts upon it2. Action: Any object experiences acceleration in presence of a net force: F = ma3. Reaction: If force F acts upon an object, –F acts upon the object where the force originates.

Classical mechanics

Inertial system: Reference frame where Newton’s 1. law applies.

any reference frame that moves with a constant velocity relative to a given inertial system, is also an inertial system and vice versa (any inertial system moves with constant velocity relative to any other inertial system)

Relativity Principle: The evaluation of an observation leads to the same conclusions about the laws of physics in any inertial system

W. Rau

S S '

V

Coordinate transformation:x = x' + Vt' y = y' z = z ' t = t'

Velocity transformation:vx = vx' + V vy = vy' vz = vz'

x = x ' + R

x ' = ( ) x ''

x = ( ) x '' + R

t = t' + Dt

→ → →

cos a sin a-sin a cos a

→ →

cos a sin a-sin a cos a

→ → →

Coordinate Transformation

v = –– = ––––––– = –– + ––– = v ' + V dx d(x '+ R ) dx ' dRdt d(t' + Dt) dt' dt

→→ →

→→→→ →

Choose: x = x‘ = 0 for t = t‘ = 0, V ║ x

Galilean law for the addition of velocities:

v = v ' + V

(V: velocity of S ' w.r.t. S )

→ → →

St1

x1

y1

x1''

y1''

S'' t1''

αx1'

y1'

S'

t1'

R = (∆x,∆y)⃑x⃑

x'⃑

W. Rau

Boat

Fog

Fog Reference frame of the boat

W. Rau

Fog

Fog

Wood

Reference frame of the wood

W. Rau

Wood

Fog

Boat

Fog

Reference frame of the wood(but observer on the boat)

W. Rau

vx = 0vy = 0

v0

vx,ball = 0vy,ball = v0 - gt

S

S'

Reference frame of the boat

W. Rau

S''v0

vx,bqll = vvy,ball = v0 - gt

vvx = vvy = 0

S

S'

Reference frame of the wood

W. Rau

vx,ball = vvy,ball = - gt

v

v0

v

S''

vx = vvy = – v0

S

S'

Reference frame of the elevator

W. Rau

How to Produce Spacetime diagrams

W. Rau

How to produce spacetime diagrams (II)

W. Rau

Spacetime diagram Boat(at rest)

Wood(moving)

Space

Tim

e

W. Rau

Boat

W. Rau

W. Rau

Spacetime diagrams

Boat (center)

Passenger (front)

Passenger (back)

Ball 1

Wood

Ball 2

Boat(center)

Passenger (front)

Passenger (back)

Ball 2

Wood

Ball 1

vB1 = v ; vB2 = – v

vB1 = vB1' + V vB1' = vB1 – V = v – V

vB2 = vB2' + V vB2' = vB2 – V = – v – V

W. Rau

Boat

Reference frame of boat and water

W. Rau

Source at rest with respect to medium

W. Rau

Source moving with respect to medium, frame of medium

W. Rau

Source moving with respect to medium, frame of source

W. Rau

Boat

Reference frame of the boat; water moving

W. Rau

Wood

Reference frame of the wood; boat moving with water

W. Rau

Source at rest with respect to medium;both are moving relative to reference frame

W. Rau

vc

Xs

v

X

Case A:Source and Receiver

at rest

Case B:Source moving with

velocity v

Case C:Receiver moving with velocity – v

W. Rau

SourceReceiver SourceReceiver

Case B

Rest frame of source(and water)

Rest frame of receiver(and water)

Case A Case C

DtR,C

x = v Dt x = 0

t = Dt

t = 0

t1

W. Rau

SourceReceiver

Case B

Rest frame of receiver(and water)

SourceReceiver

Case B

Rest frame of source

Case C

DtR,B

Rest frame of source(and water)

W. Rau

Summary

Newton’s Laws1. Inertia: v constant for F = 02. Action: F = ma3. Reaction: each force is balanced

by counter force

Reference Frames, Coordinate SystemsReference frame: “point of view”Coordinate system / transformation: Specify position / time in different frames

S S '

V

x = x' = 0 for t = t' = 0, V = Vx = const.:x = x' + Vt ; vx = vx' + V ; a = a‘

Inertial frame Reference frame where N.’s 1. law applies

Spacetime DiagramsA way to keep track of the position of objects in time

Propagation of Waves, Doppler Effect- Waves propagate with constant vc relative to medium- Observed frequency n depends on velocity of source

vs and receiver vr relative to medium:Moving source: nr = ns / (1 – v/vc)Moving receiver: nr = ns (1 + v/vc)

- Wavelength depends only on vs

Boat (center)

Passenger (front)

Passenger (back)

Ball 1

Wood

Ball 2

t

x

Galilean velocity transformationv= v'+V

W. Rau

Recommended