Upcoming Deadlines Pick up a clicker find the

Upcoming Deadlines Pick up a clicker, find the right channel, and enter Student ID Homework #10 – Outline for Second Term Paper Due Wednesday, November 10 th (This week) 20 points (10 points if late) Second Term Paper – Science Fact or Cinematic Fiction? Due Wednesday, November 17 th (Next week) 100 points (50 points if late) Homework #11 – Building a Scene in Maya Due Wednesday, November 24 th (Day before Thanksgiving) 20 points (10 points if late) For full schedule, visit course website: Art. Physics 123. pbworks. com

Character Animation Prizes Jason Spencer Galsworthy, Dreamworks Honorable Mentions: Betancourt, Ismael; Chang, Jeanie; Murray, Joelle; Myers, David; Purdy, Lisa; Reilly, Jessica; Roberts, Lucie; Roberts, Rebecca

Guest Lecture Prof. Raquel Coelho will give a special lecture on lighting in computer generated images. In class, Wed. , November 17 th Coelho has worked for studios such as Blue Sky and PDI/Dreamworks, Wildbrain Inc and Tippett Studio, as animator in films such as "Charlotte's Web", "Hellboy", "The Spiderwick Chronicles" and "Happy Feet".

Activating your Clicker * Turn on your clicker. * Enter the channel number or letter for joining this class. Hit Enter/Send key. * Clicker should read AP 123 GF 10 * 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.

Survey Question How many do you like using the blog for submitting your term paper: A) Like it a lot B) Like it C) Neutral D) Don’t like it E) Don’t like it a lot

Review Question Sparks from sparkler don’t burn skin because: A) The sparks are bright but don’t have a high temperature. B) The sparks are high temperature but they don’t have much internal energy. C) The sparks have a very low conductivity.

. . . By analogy, grains of sand that fall from a great height doesn’t have as much energy as a cannonball that falls a couple of feet. . The sparkler sparks have high temperature (5000 ºF) and high conductivity (burning iron) but are very small, with little mass. . B) The sparks are high temperature but they don’t have much internal energy. . Review Question x x

Review Question “Dry Ice” is made by freezing carbon dioxide gas to -109 °F. The term dry ice comes from: A) It’s not made with water so it’s “dry. ” B) When it melts dry ice turns directly into a gas instead of a liquid. C) When you put dry ice into water it creates a dense fog that’s not damp. D) It was first discovered by the English physicist Sir Percival Martini Dry.

Review Question B) When it melts dry ice turns directly into a gas instead of a liquid. This change of phase is called sublimation. Put dry ice into warm water to create dense fog of tiny water droplets; this is caused by the sudden release of CO 2 gas as dry ice sublimates.

Effects Animation: Hot & Cold (cont. )

Heating & Cooling Energy Decrease temperature by removing internal energy (heat flows out of object) Increase temperature by adding internal energy (heat flows into object) Energy

Heat Flow Heat always flows from high temperature objects to low temperature objects. Heat flow stops when temperatures equal. Various ways by which heat may flow. 75º Heat flows from child into air 98º 32º Heat flows from child and air into the ice cream

Conduction is heat flow by direct contact. Some materials are good thermal conductors, others are insulators. Tile floor feels colder than wood floor 98º 75º Wood is an insulator 98º 75º Tile is a conductor

Demo: Torch the Money Wrap a dollar bill tightly around a copper pipe. Put it into a flame. Paper doesn’t get hot enough to A) Paper is a good heat burn because: conductor. B) Metal is a good heat conductor.

Demo: Torch the Money B) Metal is a good heat conductor. Heat from the flame quickly passes into the copper so the paper never reaches ignition temperature (451 ºF). Paper is a heat insulator (just like wood) but in this case it’s such a thin layer the heat doesn’t have far to travel.

Air is a Poor Conductor Because air is such a poor conductor, some pizza ovens don’t have a door. Can safely put your hand in an hot oven. Metal is good conductor so you need oven mitt to touch it (cloth is poor conductor).

Convection Heat transfer in a fluid often occurs mostly by convection. Buoyancy causes warm air to rise, which carries thermal energy directly by its motion.

Demo: Candle Rising hot air above a candle carries most of the heat generated by the burning flame. Very HOT Warm Shadows reveal rising air currents of hot air.

Convection Oven Convection oven has a fan to enhance the circulation of the air, increasing the transfer of heat.

Demo: Candle in a Tube Candle stays light until the partition in the tube is removed. Why? Partition allows hot air to rise, drawing in cold air (with fresh oxygen) to fuel the candle flame. Without the partition, turbulence impedes the inflow and outflow. Convection is disrupted because tube is narrow.

Radiation Light has many different wavelengths, most of which are not visible to the eye. All light carries energy, thus transfers heat. Heat Lamp Highly reflective fire proximity suits

Heat-Ray The “heat-ray” first appeared in science fiction as the Martian weapon in H. G. Wells’ War of the Worlds (1898). War of the Worlds (1953) Mars Attacks! (1997) http: //www. youtube. com/watch? v=gs. Xn. K 0 ou. TL 8 High powered lasers are similar to H. G. Wells’ heat-ray.

Freeze-Ray There’s no current technology to create a ray that removes energy from an object. 1968 Batman cartoon Batman and Robin (1997) http: //www. youtube. com/watch? v=TNj. TW 8 ZBku. I

Emission of Radiant Energy All objects radiate light; higher the temperature the higher the light’s frequency. At room temperature the radiated light is at frequencies too low for our eyes to see. Special cameras are sensitive to this infrared radiation. 75º 98º Attics in this house were kept warm for growing marijuana.

Predator (1987) Heat vision made the Predator a deadly adversary. Beam splitter

Demo: Infrared Light Digital cameras, such as in cell phones, are sensitive to infrared light, such as from a remote control or any hot object. Microwave Transmitter Microwave Receiver

Effects Animation: Electricity & Magnetism

The Force Electrical and magnetic phenomena are the inspiration for many special effects, such as the mysterious “Force” in the Star Wars epics.

Electric Charges and Forces There are two types of charge: positive charges and negative charges REPEL ATTRACT Like charges repel, opposite charges attract.

Charging by Friction/Contact Electrons move easily so an object can become charged by rubbing electrons off the object’s surface. • Brush your hair with a plastic comb. • Walk across a carpet with plastic-soled shoes. Electrons taken off of fur onto rubber rod

Demo: Electroscope The “legs” of an electroscope separate when the electroscope is charged due to the repulsion of like charge on the two legs. Charged ebonite rod deposits negative charge (electrons) onto electroscope. “Legs”

Demo: Dial Electroscope Alternative design for electroscope Neutral Charged

Demo: Van de Graff Generator Van de Graff deposits large quantities of excess charge on its globe. A person with long hair can become a human electroscope. Repulsion also demonstrated with pie plates, Rice Krispies, etc.

Demo: Electric Pinwheel turns as charge leaves the Van de Graff from the points at the tips of the spokes. Charged Air molecules Van de Graff

Plastic Insulators Plastic insulation on step of van de Graff and charge wand keep charge from leaving the metal balls. Plastic insulation on wire prevents charge to leave wire except at the ends, where the conducting metal is exposed.

Demo: Resistance of Water Pure water has very high resistance; impurities, such as salt, lower resistance. CURRENT When salt dissolves the sodium and chlorine atoms are charged (ions). These mobile charges carry the current in the water. Light Bulb Ammeter Salty Water Power Supply

Demo: Tesla Coil Air is an insulator but at high voltages it can conduct electricity as lightning. Portable Tesla coil

Tesla Coils Very high voltages achieved with large Tesla coils. Homemade, backyard model Fry’s Superstore, Fremont CA

Faraday Cage http: //www. youtube. com/watch? v=Zi 4 k. Xg. DBFhw

Ohmic Heating Flowing electrons strike atoms in a conductor, heating the material. Toaster Hellboy (2004) http: //www. youtube. com/watch? v=OGezv. Yafez. E

Demo: Ohmic Cooking An electric current running through a hot dog generates enough heat to cook it. Strange light show when using a pickle in place of hot dog. Similar to sodium lamp discharge.

Jacob’s Ladder Ohmic heating of the air creates an electrical discharge visible. Spark begins near the bottom, where the gap is small. The current heats the air in the gap, causing it to rise since hot air is buoyant. Check out the 5 foot Jacob’s Ladder outside our classroom Jacob’s Ladder

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

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

Next Lecture Magnetism & More Homework #10 Outline for Second Term Paper Due this Wednesday! Please turn off and return the clickers!