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Journey into PhysicsCreated by Keira Favale
August 2007
Journey into Physics
Why study physics?
Career options
Areas of physics
Physicists
What is physics?
What is Physics? Of all the physical sciences, physics is the most basic and fundamental.
Physics has been described as the ‘why things work’ science as it involves discovering the rules and relationships which describe the nature of the universe. This involves everything from atoms to galaxies to the universe and everything in-between.
Even with the complexity of the world around us, one of the key ideas of physics is that there is an underlying simplicity and unity in nature. This unity does not just apply to Earth but also across the universe and throughout time.
For most of our present and future technology, physics has, or will, provide the bases for its development. Mobile phones, televisions, satellites, cameras, contact lenses, nuclear power, rockets, computers, and car design are all examples of inventions which involve the use of physics concepts. These examples highlight how interconnected physics is with modern life.
Physics provides us with a way to understand how and why things work and interact the way they do.
Home Why Study Physics?
Why Study Physics? There are many reasons to study physics. To start it is a very interesting subject,
which covers a wide range of topics including mechanics, electronics, optics, magnetism, and astronomy. But it is not just the understanding of physics concepts that can be gained from a physics course. By studying physics you have the opportunity to develop critical and creative thinking skills; skills in posing, analysing and solving questions; and the opportunity to work as a team. All of these are valuable skills which can be used throughout life.
A course in physics involves both hands on experimental investigations and theoretical analysis. Through physics we can discover how and why things work and gain a better understanding of the world around us.
The knowledge and skills gained through physics can be easy transferred into other disciplines and this adaptability can lead to a wide variety of career options.
Home Career OptionsWhat is Physics?
Career OptionsIndustries Biomedical technology Communications Computing Electronics Finance Laser/ Holograms Manufacturing Medical physics Meteorology Motor vehicle technology Photonics Power generation Research Scientific sales and management Semiconductors Teaching Telecommunications
CareersAstrophysicist BiophysicistEngineer GeophysicistParticle PhysicistPhysicist
Here are some of the many options which are available through the study of physics.
Home Why Study Physics? Areas of Physics
Areas of Physics Physical Quantities and Measurement Forces and Motion Energy and Momentum Wave Motion Optics Electricity and Electronics Magnetism and Electromagnetism Astronomy
Home Career Options Physicists
Follow the links to a range of websites to provide more information about each of these areas.
Physical Quantities and Measurement Physical Constants
Home Areas of Physics Next
Constants
Gravity g = 9.8m/s/s
Speed of Light c = 2.998x108 m/s
Planck’s constant h = 6.626x10-34Js
Mass of electron me = 9.109x10-31kg
Mass of a proton mp= 1.673x10-27kg
Scientific notation
tera- 1012 T
giga- 109 G
mega- 106 M
kilo- 103 k
milli- 10-3 m
micro- 10-6 μ
nano- 10-9 n
pico- 10-12 p
femto- 10-15 f
astronomical unit 10-10 Ǻ
Units
Temperature – Kelvin (K) Energy – Joule (J)
Capacitance – Farad (F) Force – Newton (N)
Frequency – Hertz (Hz) Pressure – Pascal (Pa)
Forces and Motion
Explorelearning – motion and force – gizmos
Skateboard Science Mechanics with animations
and film clips Vectors – Motion and Forc
es in two dimensions Newton’s Laws
Home Areas of Physics Previous Next
Scalar quantities
Vector quantities
Distance (d)
Displacement (s)
Velocity (v)
Acceleration (a)
Uniform Acceleration
v = u + at
v2 = u2 + 2as
s = 1/2(u + v)t
s = ut + 1/2at2
Newton’s Laws of Motion
F = ma
W = mg
Image from: http://www.mansfieldct.org/schools/mms/staff/hand/lawsCentripetalForce_files/image008.jpg
Energy and Momentum Work, Energy and P
ower tutorial Momentum and Ene
rgy
Home Areas of Physics NextPrevious
Kinetic energy KE = ½ mv2
Gravitational potential energy GPE = mgh
Power P = W/t
Work W = Fs cos θ
Machines – levers and pulley
Efficiency
Friction
Conservation of Momentum
Conservation of Energy
Image from: http://sol.sci.uop.edu/~jfalward/physics17/chapter3/chapter3.html
Wave Motion
Longitudinal and transverse wave motion (Dan Russell, 2006)
Explorelearning -Waves - gizmos
Home Areas of Physics NextPrevious
Electromagnetic spectrum – visible light 400-700nm
Wavelength (λ)
Period – time of one cycle (T = 1/f = 2π/ω)
Frequency – number of cycles per unit time (f)
Angular frequency ω = 2πf
Wave speed v = λf
Simple harmonic motion – depends only on the mass (m) and force constant (k)
Standing waves – a wave that stays in the same position
Traveling waves – a wave that moves along the medium
Image from: http://uk.encarta.msn.com/media_461517875_761564098_-1_1/Types_of_Wave_Motion.html
Optics
Science, Optics and You Thin lens java applet written by
Fu-Kwun Hwang
Image formed by a converging lens
The Electromagnetic spectrum Explorelearning
– Optics - gizmos
Home Areas of Physics NextPrevious
Object distance (u)
Image distance (v)
Focal length (f)
Snell’s Law 1/v + 1/u + 1/f
Magnification M = |v/u| = Hi (height of image)/Ho (height of object)
Ray diagrams
Angle of incidence (i)
Angle of refraction (r)
Refractive index (n)Image from: http://www.exploratorium.edu/imagery/stills/Refractive_mixing.jpg
Electricity and Electronics
Explorelearning – Electronics -gizmos
Home Areas of Physics NextPrevious
Static Electricity – like charges repel, unlike charges attract
Electric Fields
Series and Parallel Circuits
Ohm’s Law V = IR
Kirchoff’s Laws P = VI; W=VIt
Resistance (R) – combinations in series and parallel
Conductors – charge can easily move through material
Insulators – charge can not easily move through material
P-type and N-type semiconductors
Image from: http://www.dorsetforyou.com/media/images/e/t/CompletedPrintedCircuitBoard.jpg
Magnetism and Electromagnetism
Explorelearning – Magnetism - gizmos
Home Areas of Physics NextPrevious
Magnetic Poles – north-seeking and south-seeking
Magnetic fields – permanent magnets, current carrying wires, loops, solenoid
Magnetic Flux – the number of magnetic field lines passing through a surface
B = kI/r; B = 2πkNI
Units – tesla (one newton per ampere per meter),
EMF is proportional to the rate of change of magnetic flux (Φ)
EMF = BLv; EMF = -NΔΦ/Δt
Generators and TransformersImage from: http://en.wikipedia.org/wiki/Magnetism
Astronomy
Introduction to the sky Main Sequence Stars
Home Areas of Physics Previous Physicists
The expanding universe
Background radiation
Black holes
Stars, Planets and Galaxies
Kepler’s Laws 1. Each planet moves in an elliptical orbit, with the sun at one
focus of the ellipse
2. A line from the sun to a given planet sweeps out equal areas in equal time
3. The periods of the planets are proportional to the 3/2 powers of the major axis lenghts of their orbits
Image from: http://solar.physics.montana.edu/gallery/intro.html
Physicists Marie Curie Albert Einstein Michael Faraday Stephen Hawking James Maxwell Isaac Newton
Home Areas of Physics Finish
Follow the links to a range of websites which cover the life and achievements of each of these physicists.
Marie Curie (7/11/1867 – 4/07/1934)
Marie Sklodowska Curie Biography Marie and Pierre Curie a
nd the Discovery of Polonium and Radium
Home Physicists Next
Image from: http://hep.ucsb.edu/people/hnn/mcurie.jpg
Nobel Prize in Physics 1903 – awarded to Marie and Pierre Curie for the discovery of radium and polonium; award was shared with Antoine Henri Bacquerel (discovered natural radioactivity)
Nobel Prize in Chemistry 1911 – awarded to Marie Curie for isolating radium and studying its chemical
properties
Throughout the First World War, Marie Curie was engaged intensively in equipping more than 20 vans that acted as mobile field hospitals and about 200 fixed installations with X-ray apparatus
Albert Einstein (14/03/1879 – 18/04/1955)
Biography Einstein – Image and Impact
Home Physicists Next
Nobel Prize in Physics 1921 – for his services in Theoretical Physics, and his discovery of the law of the photoelectric effect
The Photoelectric Effect – Einstein postulated that a beam of light consists of small packages of energy called photons or quanta – E = hf = hc/λ
Special Theory of RelativityFirst Postulate – Principle of relativity: The laws of physics are the same in every inertial frame of reference
Second Postulate – The speed of light in a vacuum is the same in all inertial frames of reference and is independent of the motion of the source
Implications: (1) Events that are simultaneous for one observer may not be simultaneous for another (2) When two observers moving relative to each other measure a time interval or a length, they may not get the same results
Image from: http://hep.ucsb.edu/people/hnn/Albert_Einstein.jpg
Previous
Michael Faraday (22/09/1791 – 25/08/1867)
Michael Faraday Faraday
Home Physicists Previous Next
First introduced the concept of field lines (electric field lines)
Faraday’s icepail experiment – based on the same principle is used in a Van de Graaff electrostatic generator and forms the basis for electrostatic shielding
Faraday and Henry discovered that moving a magnet near a conducting loop can cause a current in the loop
Faraday’s Law of induction: the induced EMF in a closed loop equals the negative of the time rate of change of magnetic flux through the loop
Image from: http://www.abdn.ac.uk/~u02rjr4/px2013/Faraday.htm
Stephen Hawking (8/01/1942)
Official Website
Home Physicists Previous
With Roger Penrose, Hawking showed that Einstein's General Theory of Relativity implied space and time would have a beginning in the Big Bang and an end in black holes.
Hawking discovered that black holes should not be completely black, but should emit radiation and eventually evaporate and disappear.
Another conjecture he has made is that the universe has no edge or boundary in imaginary time.
Image from: http://hep.ucsb.edu/people/hnn/hawking.jpg
Next
James Maxwell (13/06/1831 – 5/11/1879)
Maxwell Year 2006 James Clerk Maxwell: a force for physics
Home Physicists Previous Next
The first person to truly understand the fundamental nature of light
Discovered the basic principles of electromagnetism – Maxwell’s Equations
Displacement current iD – electromagnetic theory
Image from: http://hep.ucsb.edu/people/hnn/maxwell.jpg
Isaac Newton (25/12/1642 – 20/03/1727)
Newton, Isaac Sir Isaac Newton
Home Physicists Previous
Newton’s Laws of Motion – foundation of classical mechanics (or Newtonian mechanics)
First Law – An object that is at rest will remain at rest or an object that is moving will continue to move in a straight line with constant speed, if and only if the net force acting on that object is zero.
Second Law – The force of an object is equal to the mass of an object multiplied by its acceleration (F=ma)
Third Law – All forces come in pairs and these two forces are equal in magnitude and opposite in direction (equal and opposite)
Newton’s Law of Gravitation F = G mAmB
d2
Image from: http://hep.ucsb.edu/people/hnn/newton_1.jpg
Finish
Only just the beginning… This is only a brief
introduction to the amazing journey through Physics. For more information about Physics courses contact your science teacher, guidance officer, or choice of university.
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