Journey into Physics

1. Journey into Physics Created by Keira Favale August 2007

2. Journey into Physics Career options What is physics? Areas of physics Why study physics? Physicists

3. What is Physics? • Of all the physical sciences, physics is themost basic and fundamental. Physics has been described as the‘why things work’ scienceas 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 anunderlying 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 tounderstand how and why things workandinteract the way they do. Home Why Study Physics?

4. Why Study Physics? • There are many reasons to study physics. To start it is a very interesting subject, which covers awide range of topicsincluding 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 todevelop 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 candiscover 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 awide variety of career options. Home Career Options What is Physics?

5. Career Options Industries • 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 Here are some of the many options which are available through the study of physics. • Careers • Astrophysicist • Biophysicist • Engineer • Geophysicist • Particle Physicist • Physicist Home Why Study Physics? Areas of Physics

6. Areas of Physics • Physical Quantities and Measurement • Forces and Motion • Energy and Momentum • Wave Motion • Optics • Electricity and Electronics • Magnetism and Electromagnetism • Astronomy Follow the links to a range of websites to provide more information about each of these areas. Home Career Options Physicists

7. Physical Quantities and Measurement 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 • Physical Constants Units Temperature – Kelvin (K) Energy – Joule (J) Capacitance – Farad (F) Force – Newton (N) Frequency – Hertz (Hz) Pressure – Pascal (Pa) Home Areas of Physics Next

8. Forces and Motion • Explorelearning – motion and force – gizmos • Skateboard Science • Mechanics with animations and film clips • Vectors – Motion and Forces in two dimensions • Newton’s Laws 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 Home Areas of Physics Previous Next

9. Energy and Momentum • Work, Energy and Power tutorial • Momentum and Energy 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 Home Areas of Physics Previous Next

10. Wave Motion 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 • Longitudinal and transverse wave motion (Dan Russell, 2006) • Explorelearning -Waves - gizmos Image from: http://uk.encarta.msn.com/media_461517875_761564098_-1_1/Types_of_Wave_Motion.html Home Areas of Physics Previous Next

11. 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 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 Home Areas of Physics Previous Next

12. Electricity and Electronics 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 • Explorelearning – Electronics -gizmos Image from: http://www.dorsetforyou.com/media/images/e/t/CompletedPrintedCircuitBoard.jpg Home Areas of Physics Previous Next

13. Magnetism and Electromagnetism • Explorelearning – Magnetism - gizmos 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 Transformers Image from: http://en.wikipedia.org/wiki/Magnetism Home Areas of Physics Previous Next

14. Astronomy • Introduction to the sky • Main Sequence Stars • The expanding universe • Background radiation • Black holes • Stars, Planets and Galaxies • Kepler’s Laws • Each planet moves in an elliptical orbit, with the sun at one focus of the ellipse • A line from the sun to a given planet sweeps out equal areas in equal time • 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 Home Areas of Physics Previous Physicists

15. Physicists • Marie Curie • Albert Einstein • Michael Faraday • Stephen Hawking • James Maxwell • Isaac Newton Follow the links to a range of websites which cover the life and achievements of each of these physicists. Home Areas of Physics Finish

16. Marie Curie (7/11/1867 – 4/07/1934) • Marie Sklodowska Curie • Biography • Marie and Pierre Curie and the Discovery of Polonium and Radium 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 Image from: http://hep.ucsb.edu/people/hnn/mcurie.jpg Home Physicists Next

17. Albert Einstein (14/03/1879 – 18/04/1955) 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 Relativity First 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 • Biography • Einstein – Image and Impact Image from: http://hep.ucsb.edu/people/hnn/Albert_Einstein.jpg Home Physicists Previous Next

18. Michael Faraday (22/09/1791 – 25/08/1867) • Michael Faraday • Faraday First introduced the concept of field lines (electric field lines) Faraday’s icepail experiment – based onthe 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 Home Physicists Previous Next

19. Stephen Hawking (8/01/1942) • Official Website 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 Home Physicists Previous Next

20. James Maxwell (13/06/1831 – 5/11/1879) • Maxwell Year 2006 • James Clerk Maxwell: a force for physics 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 Home Physicists Previous Next

21. Isaac Newton (25/12/1642 – 20/03/1727) • Newton, Isaac • Sir Isaac Newton 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 Home Finish Physicists Previous

22. 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. Home Exit