ENPH/PHYS 242 Fall 2016
Homework Assignment #2 - Solution
1. Binary Stars [a) 1; b) 1; c) 2]
A binary star system has a distance from Earth of 42.2 light years. The distance between the stars
is 1.08 1011 m and the rotation period is 104 days. Assume equa
ENPH/PHYS 242 Fall 2016
Homework Assignment #9 - Solution
1. Photoelectric Effect [a) 1; b) 1; c) 3]
We have a light source with adjustable wavelength but fixed power ( = 23.8 mW). The light is
emitted in a narrow cone, so all available power can be direc
ENPH/PHYS 242 Fall 2016
Homework Assignment #10 - Solution
2. Bragg Reflection [a) 2; b) 3]
Bragg reflection is used to analyse the composition of the radiation form an x-ray tube. The
analysing crystal is a LiF single crystal with a lattice constant 1 of
ENPH/PHYS 242 Fall 2016
Homework Assignment #5 - Solution
Trouble with Space Traffic [a) 4; b) 2; c) 1; d) 1; e) 2]
Albert travels in his spaceship to Spaceton (formerly also known as Space Town). As he
approaches a narrow gap between two big space statio
ENPH/PHYS 242 Fall 2016
Homework Assignment #1 - Solution
Particles and Waves [a) 1; b) 2; c) 4; d) 1; e) 2]
Three friends go out on a lake with a paddle boat. The boat is moving with = 2.0 m/s on the
shortest way towards the other shore. Exactly in the m
ENPH/PHYS 242 Fall 2016
Homework Assignment #8 - Solution
Thermal Radiation [ a) 1p; b) 1p; c) 4p; d) 4p ]
The emission of an incandescent light bulb is well described by a black body spectrum.
a) The most abundant wavelength is 1480 nm. What is the tempe
ENPH/PHYS 242 Fall 2016
Homework Assignment #3 - Solution
Space-mail [a) 1; b) 2; c) 2; d) 3; e) 2; BONUS: 2]
Albert owns a comfortably large spaceship with a proper length
= 99 m. He is planning on
visiting a space station with wireless internet to check
ENPH/PHYS 242 Fall 2016
Homework Assignment #7 - Solution
1. Thermal excitation in a gravitational system [ a) 1p; b) 2p; c) 1p; d) 2p ]
A crazy physicist installs a cylindrical tube in the CN tower, reaching from the bottom to highest
visitors platform a
ENPH/PHYS 242 Fall 2016
Homework Assignment #4 - Solution
Relatively Pretty Fireworks [a) 4; b) 2; c) 3; d) 2]
It was both Newtons and Einsteins hobby to develop sophisticated fireworks. One of Newtons
masterpieces can be described as a small rocket, that
ENPH/PHYS 242 Fall 2014
Quiz 4 - Solution
Wednesday November 19, 13:30 pm
Question 1: [4]
A silicon crystal with a lattice spacing of 0.54 nm is exposed to characteristic x-rays of copper
with an energy of 8.9 k V.
a) What is the smallest angle (in degree
ENPH/PHYS 242 Fall 2014
Quiz 2 - Solution
Wednesday October 15, 13:30 pm
Question 1: [4 points]
A red LED emits light with a wavelength of 682 nm in all directions. It moves with a high speed relative
to an observer who sees the light being green at 551 n
ENPH/PHYS 242 Fall 2013
Name:
Student Number:
Quiz 3 - Solution
Wednesday November 05, 13:30 pm
[If you feel information is missing anywhere: make a reasonable assumption and clearly state what your
assumption is]
Question 1: [4 points]
Assume you observe
ENPH/PHYS 242 Fall 2014
Quiz 1 - Solution
Wednesday September 24, 13:30 pm
Question 1: [5 points]
The train paradox describes a situation where light is emitted in the centre of a train. Within the
reference frame of the train the light should arrive at t
ENPH/PHYS 242 Fall 2014
Tutorial Week 2
Wednesday September 17, 13:30 pm
1. Spacetime Diagrams
a) A visit to the zoo
A lion in a cage moves with constant velocity back and forth, turning around when he
reaches the ends of his cage. A boy and a girl get to
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ENPH/PHYS 242 Fall 2014
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1.3.4 Velocity Transformation, Four-Velocity
After we have derived the relativistically correct transformation law
for the space and time coordinates we go to the next step and discuss
the velocity transformation. This mean
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ENPH/PHYS 242 Fall 2013
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Cosmic Ray Muons and Length Contraction
For a change we now will discuss a real experiment as performed by
Frisch and Smith, two US American physicists in 1963. This
experiment is concerned with the measurement of cosmic ra
ENPH/PHYS 242 Fall 2014
Relativity and Quanta
Lecture Notes
Wolfgang Rau
Queens University
ENPH/PHYS 242 Fall 2014
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ENPH/PHYS 242 Fall 2014
L 01
Introduction
At the end of the 19th century many physicists believed that the basic
problems of physics had b
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ENPH/PHYS 242 Fall 2013
L 04
1.2 Speed of Light
1.2.1 Historical Introduction
To our everyday experience light seems to arrive from its source
instantaneously. For a long time in history most people believed that
this is actually true. The first docume
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ENPH/PHYS 242 Fall 2014
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1.3.7 Relativistic Dynamics
The basic equation for classical dynamics is Newtons second law:
In special relativity we use the same relation between force and
momentum:
We can calculate the derivative of
explicitly a
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ENPH/PHYS 242 Fall 2014
L 13
Cosmic Microwave Background
Shortly after the Big Bang the Universe was very dense and hot. Since
then it has expanded and cooled down. However, we still can measure
the thermal radiation from the Big Bang which today has a