January 10, PHY 2049 Spring 2005 Dr. Jeff Bindell

January 10, InstructorDr. Jeffrey Bindell ScheduleM,W,F 11:30 AM – 12:20 PM Office HoursApproximately 12:45 to 1:45 on class days. Other times by appointment. Drop-ins always welcome. Phone s will always be answered. Web Sitewww.physics.ucf.edu/~bindell

January 10, On the WebSite  Copies of many of the overheads that will be used in class. (Today’s Included)  Click on: PHY 2049 Lecture SectionPHY 2049 Lecture Section  Copies of any PowerPoint presentations used in the class.  The syllabus (watch it for any changes)  Helpful hints  Unhelpful hints

January 10, Textbook Information TextbookFundamentals of Physics – Volume 2 or entire textbook Halliday, Resnick and Walker Seventh Edition Wiley ISBN (vol 2) RequiredWebAssign Registration. This may be purchased from the bookstore or you may register on-line at and click on access codes. Highly Recom mended “The Portable TA – A Physics Problem Solving Guide” Volume II by Andrew Elby, Prentice Hall (1998) ISBN Available USED on amazon.com. The campus bookstore may have them wither in stock or can order it for you.

January 10, We will begin using WebAssign THIS WEEK, so do not delay registering. WebAssign HWs may NOT be always announced in class so please check the site every day or two.

January 10, WebAssign  Homework Assignments  Communications Page to instructor requests for extensions  I am easy with these but you must include a reason. requests for assistance  I don’t always respond to these. Forums Announcements about tests, quizzes, changes, etc.  NOTE – There is already an assignment posted. An “Intro to Using WebAssign”

January 10, Weighty Matters PortionWeight Examinations (3)3 Final Examination 2 Homework2 In Class Quizzes1

January 10, What’s the score? ScoreGrade A 75-84B 60-74C 50-59D

January 10, Quizzes  Expect a quiz every week.  Usually on Friday.  Quiz will be either 1 problem similar to the WebAssign problems, A few multiple choice questions.  I do not use “pop” quizzes.  RateMyProfessors says that my tests are hard. It also says some other nasty things!

January 10, MAKE-UP EXAMS Make-up quizzes and examinations will not be allowed unless there is a very compelling personal reason for doing so. Included among excused absences are death (yours, a family member or close friend), illness in the family, family emergencies and excused absence due to participation in sporting events or other sanctioned UCF activities Initial requests must be in writing or .

January 10, About the course  PHYSICS FOR ENGINEERS AND SCIENTISTS II IS HARD!!  Everything builds on previous material.  If you wait until exams to study you are doomed.  Keep up with your homeworks and reading assignments.  Study a lot!  Ask for help if you need it.

January 10, Course Overview  Electricity Charges Moving Charges (currents) Forces on charges Potential (an energy concept) Types of materials Electrical Elements & Circuits Some additional topics that will drive you crazy. Laterally!

January 10, More Course  Magnetism Magnets Magnetic Fields Forces on charges in magnetic fields Creating Magnetic Fields Induction & Inductance AC Circuits  Additional Optics  diffraction  interference

January 10, The “Flow” Mechanics Electricity Induction Maxwell Magnetism OPTICS

January 10, DEMO NOTICE

January 10, A Quick Experiment

January 10, Rubbings

January 10, The Real Deal

January 10, Forces

January 10, Let’s try it  Rod/Cloth Experiments Conclusions  Van der Graaf Demo What’s going on here?

January 10,

January 10, Photo

January 10,

January 10, What’s Going On?  All of these effects involve rubbing two surfaces together.  Or pulling two surfaces apart.  Something is on each of these objects.  We call this “something” CHARGE.

January 10, We have also observed that there must be TWO kinds of charge.  Call these two types positive (+) negative(-)  We “define” the charge that winds up on the rubber rod when rubbed by the dead cat to be NEGATIVE.  The charge on the glass rod or the dead cat is defined as POSITIVE.

January 10, Effect of Charge

January 10, Probable First Observation of Charge

January 10, Idiot! If lightening had actually traveled down the kite string, old Ben Franklin would have been toast!

January 10, Don’t Mess With Mother Nature St. Elmo’s Fire Top of Mast

January 10, History  600 BC Thales of Miletos rubs amber (electron in Greek) with cat fur and uses it to pick up feathers.  Important questions: Why was he doing this? Didn’t he have a job?? What happened to the skinned cat?

January 10, Amber Million years ago large stands of forests in some parts of the world began to seep globs of sticky resin! This aromatic resin oozed down the sides of trees, as well as filling internal fissures, trapping debris, such as seeds, leaves, feathers and insects. As geologic time progressed the forests were buried and the resin hardened into a soft, warm, golden gem, known as amber. Amber is the fossilized resin of ancient trees which forms through a natural polymerization of the original organic compounds. Most of the world's amber is in the range of million years old.Amber

January 10, What happens when two surfaces touch or rub? Bonding!

January 10, Example - Tape

January 10, When two of the following materials are rubbed together under ordinary circumstances, the top listed material becomes positively charged and the lower listed material becomes negatively charged. MORE POSITIVE rabbit's fur glass mica nylon wool cat's fur silk paper cotton wood acrylic cellophane tape polystyrene polyethylene rubber balloon saran wrap MORE NEGATIVE The Triboelectric Series No!

January 10, Summary - Rubbings

January 10, What have we found?  There are TWO types of charge. Positive Negative  Like Charges Attract  Un-Like charges repel  The force between charges increases as they are brought closer together.  This charge separation results from chemical bonds which are severe in the pocess.

January 10, The Electroscope

January 10, Forces Between Charges Q1Q1 Q2Q2 AttractRepel ++X +-X -+X --X

January 10, NEXT TRANSFER OF CHARGE