Upcoming Deadlines

1. Pick up a clicker, find the right channel, and enter Student ID Upcoming Deadlines Second Term Paper – Science Fact or Cinematic Fiction? Due Wednesday, November 17th (Next week) 100 points (50 points if late) Homework #11 – Building a Scene in Maya Due Wednesday, November 24th (Day before Thanksgiving) 20 points (10 points if late) For full schedule, visit course website: ArtPhysics123.pbworks.com

2. Activating your Clicker * Turn on your clicker. * Enter the channel number or letter for joining this class. Hit Enter/Send key. * Clicker should read AP123S258 * Type in your student ID; hit Enter/Send. Clicker is now ready to use; leave it on. Hit any key to wake the clicker from sleep mode.

3. Survey Question How much experience do you have using AutoDesk Maya? • A lot of experience • A little experience • Never used it but know of it • Not familiar with it at all

4. Review Question • Which of these is not a mechanism for heat transfer? • Conduction • Radiation • Reduction • Convection

5. Heat Transfer C) Reduction Radiation Convection Conduction

6. Review Question + + • Fill in the blanks: • Two objects with positive charge _______ each other and two objects with negative charge _______ each other. • Attract … Repel • Repel … Attract • Attract … Attract • Repel … Repel - -

7. Electric Charges and Forces D) Repel … Repel Like charges repel, opposite charges attract. REPEL REPEL ATTRACT Note that by Action/Reaction, the force on each object is always equal in magnitude, opposite in direction.

8. Review Question Flowing electrons strike atoms in a conductor, heating the material. This type of heating is named after: • André-Marie Ampère • Nicola Tesla • Thomas Edison • Georg Ohm • Alessandro Volta Toaster

9. Ohmic Heating Georg Simon Ohm (1789 –1854) was a German physicist. As a high school teacher, Ohm began his research with the recently invented electrochemical cell, invented by Italian Count Alessandro Volta. Using equipment of his own creation, Ohm determined that there is a direct proportionality between the potential difference (voltage) applied across a conductor and the resultant electric current – now known as Ohm's law. Georg Ohm Ohmic heating is also called Joule heating, first studied by James Prescott Joule in 1841

10. Effects Animation:Electricity & MagnetismPart 2

11. WARNING Strong magnets will be passed around the room. Keep these magnets away from iPods and laptops (especially my laptop)!

12. Electrocution Electrocution (death by electric shock) is usually due to ohmic heating of the internal organs of the body. True or False

13. Electrocution False It is due to the disruption of the nervous system, especially that which controls the heart beat.

14. Nervous System Nervous systems in animals use electrical currents to signal the contraction and relaxation of muscles. Frog leg jumps when electrical current passes through it.

15. Presto (2008) Common visual gag is the uncontrollable twitching of a person’s muscles. Notice Jacob’s Ladder in Presto’s hair http://www.youtube.com/watch?v=mw-fs19kTGM

16. Sherlock Holmes (2009) The electric shock does not exert a force, rather it causes muscles to contract; this scene is not realistic.

17. Conduction in Human Heart The most important electrical signal in our body is the periodic signal that contracts and relaxes our heart muscle to pump blood. Without a constant flow of blood the brain can suffer permanent damage. SA AV

18. Electric Shock The damaging effects of shock are the result of electrical current passing through the body. Current depends on the voltage and on electrical resistance. When dry, skin’s resistance around 100,000 . Resistance drops as low as 100  when wet and salty. Effects of Electric Shock on Human Body

19. Frankenstein (1931) Electricity brings Frankenstein’s monster to life in the 1931 horror classic yet it’s not mentioned in the original book, written in 1818 by Mary Shelley. Bolts for electrical contact http://www.youtube.com/watch?v=8H3dFh6GA-A

20. http://www.youtube.com/watch?v=rKc4BWvWtuM Magneto Magneto, the villain in the X-men movies, controls the force of magnetism. The majority of the animation and lighting in this scene was done in Maya.

21. Magnetic Forces General observations regarding magnets: Iron (and a few other metals) are ferromagnetic, which means they can become magnetized. Magnets attract ferromagnetic metals. Two magnets can either attract or repel each other depending on poles. Iron Ore

22. Ferromagnetic Metals Ferromagnetic metals have similar atomic structure. Spin of the electron in these metals produces a net magnetic field Iron, Cobalt, Nickel Many ferromagnetic alloys (blends of metals)

23. Demo: Magnetism & Money Most US coins are not made of ferromagnetic materials but many other countries use iron steel in their currency. Some Euro coins contain steel Some pennies were made of steel during World War II Buffalo nickels are 25% nickel metal, which is ferromagnetic Iron is in the ink used in US paper currency to avoid counterfeiting.

24. Magnetizing Iron Magnetic domains can be induced to align by an external magnetic field. S N Strong Magnet N S N Strong Magnet

25. Demo: Magnetizing Iron Magnetic domains in iron nails are induced to align by proximity of the strong magnet Each nail becomes itself a magnet, which in turn magnetizes the nail below it, forming a chain. When the strong magnet is removed, most of the domains un-align and nail lose most of their magnetization.

26. Demo: Demagnetizing Iron Iron nail is attracted to the large magnet due to alignment of domains in the nail. Heat the nail to a high temperature and the domains become randomized so the nail is no longer attracted to the magnet.

27. Magnets & Wile E. Coyote Wile E. Coyote is surprised when a big metal can of TNT comes flying in, pulled in by his magnet. In reality, the force of the can on the magnet is just as strong as the pull of the magnet is on the can of TNT. Trueor False?

28. Magnets & Wile E. Coyote From “Zipping Along” True. Another example of action/reaction principle (Newton’s Third Law). Action force is magnet pulling TNT can. Reaction force is TNT can pulling magnet.

29. Demo: Electromagnets N Iron Bar Electromagnet created by passing current through a coil of wire. Electromagnet is stronger when an iron bar is inserted within the coil. Wire Coil S Connect to battery or power supply

30. Loudspeakers Loudspeaker has a membrane but oscillations are created by variations in electrical current, which cause an electromagnet to be pulled towards and away from a second, permanent magnet. These oscillations cause the membrane of the loudspeaker to vibrate with the same frequency as the oscillations in the electrical current. Headphones work essentially the same way, they’re just smaller.

31. Earth’s Magnetic Field The configuration of the Earth's magnetic field resembles a strong bar magnet located near the center of the Earth. The magnetic South pole is near the geographic North pole (so North pole of compass attracted towards Northern direction). There isn’t an giant underground magnetized chunk of iron; Earth’s interior is simply too hot. N S

32. Origin of Earth’s Magnetic Field Earth is an electromagnet with electric currents deep below the surface. Moving charges, looping around within the molten part of the Earth, create the magnetic field. These currents are possibly the result of thermal convection rising from the central core combined with the rotation of the Earth about its axis.

33. Demo: Electric Motor Can create an electrical motor by passing a current through a set of electro-magnets mounted on a rotating shaft. Current out Current in Electro-magnets

34. N S N S Electric Motor, Analyzed Current Electromagnet mounted on a shaft with opposing magnets on each side. Current direction always such that electromagnet is repelled, causing shaft to turn. N S N S Current

35. Demo: Magnetic Force & Current Moving charges in an electric current experience a force due to magnetic field.

36. Demo: Crooke’s Tube Electron beam in a Crooke’s tube is deflected when a magnet is brought near the tube.

37. Television Tube Electron beams, deflected by magnetic fields, are used to create TV images. Electromagnets

38. Demo: Magnets & TV sets Picture on a TV set is distorted by presence of a magnet since picture formed by an electron beam. Warning: Strong magnets can permanently damage a television or a computer. N S

39. Demo: Magnet Induces Current Voltage and current are induced when a magnet moves towards or away from a coil of wire. Faster the magnet’s motion, the greater the induced current.

40. Demo: Electric Generator DC Output Turn the shaft by hand and as the coils pass the magnets a voltage is induced. DC current is generated. SHAFT Magnet Magnet Coils

41. Magnetic Recording Write data by magnetizing recording media (e.g., video tape, hard disk) using electromagnets. Data is read back using the induced current produced when magnetized media moves past receiver coils (reverse of writing data). Hard disk

42. EMP (ElectroMagnetic Pulse) A strong, rapidly fluctuating magnetic pulse can induce high voltage, causing strong currents. In 1962, a nuclear test in the Pacific produced an EMP that knocked out 300 streetlights and telephone service in the Hawaiian islands, 900 miles from the explosion. Starfish Prime, as seen from Honolulu

43. Call of Duty: Modern Warfare 2 (2009) In the “Second Sun” campaign mission a nuclear missile creates a high-altitude EMP. Streetlights explode, helicopters fall out of the sky, and electronic equipment on weapons is “fried.”

44. Next LectureLighting & OpticsPart I Please turn off and return the clickers!