Upcoming Deadlines

Second Term Paper Science Fact or Cinematic Fiction?Due Wednesday, April 21st (This Wednesday!)100 points (50 points if late)

Homework #11 Building a Scene in MayaDue Wednesday, April 28th (Next week)20 points (10 points if late)

There are no more furlough days for this class this semester.

For full schedule, visit course website:ArtPhysics123.pbworks.comPick up a clicker, find the right channel, and enter Student ID

Second Term PaperYour second term paper, Science Fact or Cinematic Fiction, due Wednesday.

Length (1500 words), structure, grading rubric, etc. similar to the first term paper.

Due by 8am on Wednesday, April 21st .100 points (if late, 50 points)

Final ExamFinal Exam will have of 10 short essay questions on material covered in lecture.

Final exam counts for 50 points.

See website for sample exam from last semester.

Final exam is scheduled will be on Wednesday, May 19th in this room from 12151430.

Wanted: 3D GlassesIf you have any extra 3D glasses youre willing to donate, please bring them in.

Both anaglyph (red/blue) and polarized (Real3D) are needed.

Guest LectureProf. Raquel Coelho will give a special lecture on lighting in computer generated images.

In class, Wed., April 28th 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".

http://www.youtube.com/watch?v=BE827gwnnk4Acoustic ResonanceIf amplitude of the sound is sufficiently large, resonant vibrations can shatter a wine glass.

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.

Survey QuestionHow many do you like using the blog for submitting your term paper:Like it a lotLike itNeutralDont like itDont like it a lot

Review QuestionSparks from sparkler dont burn skin because:

The sparks are bright but dont have a high temperature.The sparks are high temperature but they dont have much internal energy.The sparks have a very low conductivity.

Review QuestionB) The sparks are high temperature but they dont have much internal energy.x xThe sparkler sparks have high temperature (5000 F) and high conductivity (burning iron) but are very small, with little mass.

By analogy, grains of sand that fall from a great height doesnt have as much energy as a cannonball that falls a couple of feet.. . . . . . . .

Effects Animation:Hot & Cold (cont.)

Heating & CoolingEnergyIncrease temperature by adding internal energy (heat flows into object)EnergyDecrease temperature by removing internal energy (heat flows out of object)

Transfer of Thermal EnergyThere are three primary mechanisms for the transfer of thermal energy:

Conduction Direct contact of objects Convection Fluid motion carrying energy Radiation Light shining on an object

Lets see examples of each mechanism.

ConductionConduction is heat flow by direct contact.Some materials are good thermal conductors, others are insulators.98759875Wood is aninsulatorTile is aconductorTile floor feels colder than wood floor

Air is a Poor ConductorCan safely put your hand in an hot oven.Metal is good conductor so you need oven mitt to touch it (cloth is poor conductor).Because air is such a poor conductor, some pizza ovens dont have a door.

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

Demo: CandleVery HOTWarmShadows revealrising air currents of hot air.Rising hot air above a candle carries most of the heat generated by the burning flame.

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

Demo: Candle in a TubeCandle 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.

Fiberglass InsulationAir is a poor thermal conductor but easily transfers heat by convection.Fiberglass insulation is mostly air, with the fibers disrupting the convection flow.

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

Heat-RayThe heat-ray first appeared in science fiction as the Martian weapon in H.G. Wells classic novel, War of the Worlds (1898).http://www.youtube.com/watch?v=gsXnK0ouTL8War of the Worlds (1953)Mars Attacks! (1997)High powered lasers are similar to H.G. Wells heat-ray.

Freeze-RayTheres no current technology to create a ray that removes energy from an object.http://www.youtube.com/watch?v=TNjTW8ZBkuI1968 Batman cartoonBatman and Robin (1997)

Emission of Radiant EnergyAll objects radiate light; higher the temperature the higher the lights 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.Attics in this house were kept warm for growing marijuana.9875

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

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

MicrowaveTransmitterMicrowaveReceiver

Effects Animation:Electricity & Magnetism

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

Electric Charges and ForcesThere are two types of charge: positive charges and negative chargesREPELREPELATTRACTLike charges repel, opposite charges attract.

Charging by Friction/ContactElectrons move easily so an object can become charged by rubbing electrons off the objects 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: ElectroscopeThe 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 ElectroscopeAlternative design for electroscopeChargedNeutral

Demo: Van de Graff GeneratorVan 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 PinwheelPinwheel turns as charge leaves the Van de Graff from the points at the tips of the spokes.Van deGraffChargedAir molecules

Plastic InsulatorsPlastic 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: Tesla CoilAir is an insulator but at high voltages it can conduct electricity as lightning.PortableTesla coil

Tesla CoilsVery high voltages achieved with large Tesla coils.Homemade, backyard modelFrys Superstore, Fremont CA

Faraday Cagehttp://www.youtube.com/watch?v=Zi4kXgDBFhw

Ohmic HeatingFlowing electrons strike atoms in a conductor, heating the material.

Toasterhttp://www.youtube.com/watch?v=OGezvYafezEHellboy (2004)

Next LectureMore Electricity + Magnetism

Second Term Paper due this Wednesday!Please turn off and return the clickers!

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