Lecture 1 Lecture 1 --CoulombCoulomb’’s Laws LawChapter 25 Chapter 25 --Tuesday January 9thTuesday January 9th•Introduction and overview of the course•Discussion of syllabus and policies•Overview of the course web page•Electrostatics•Charge and charging•Conductors and insulators•Coulomb’s Law•Scalar and vector notation•Discrete charge distributions (superposition principle)•Continuous charge distributionsReading: pages 567 thru 580 (chapter 25) in HRKReading: pages 567 thru 580 (chapter 25) in HRKRead and understand the sample problemsRead and understand the sample problemsWebAssign assignment: set 1, due Thu. 18th at 11:59pmWebAssign assignment: set 1, due Thu. 18th at 11:59pmThere is also a practice assignment (not counted in grade)There is also a practice assignment (not counted in grade)Graded problem: Ch. 25 Graded problem: Ch. 25 ––Prob. 10Prob. 10Practice problems: Ch. 25 Practice problems: Ch. 25 --Ex. 1, 9, 19; Prob. 3 & 11Ex. 1, 9, 19; Prob. 3 & 11http://www.phys.ufl.edu/~hill/teaching/2005/2061/index.htmThe PHY2061 Course Web SiteThe PHY2061 Course Web Site•All information is posted here•Syllabus, homework and exam policies, etc..•Links to on-line homework pages (incl. deadlines) •Course schedule with exam dates•Solutions to exams (and practice questions)•DON’T FORGET TO DO THE DAILY HOMEWORK!!•No excuse for not getting close to 100% for the weekly (WebAssign) homework sets•YOU NEED TO PURCHASE REMOTES FOR THE IN-CLASS QUIZZES (CONSULT THE COURSE WEB PAGE)About the text bookAbout the text book•Many useful exercises and problems at ends of chapters•Multiple choice questions (may be used for JiTT/HiTT)•Conceptual questions (ask me if you do not understand) •Exercises are similar to the example problems in main text•Problems require thinking outside of the box •All odd numbered Exercises and Problems have the numerical answers at the back of the text book•I will assign a few of these problems as optional work, and I will post solutions after the corresponding WebAssign deadlines•Take some time to study the appendices at the end of the book. In particular, you will find integrals and other useful trigonometric identities.The PHY2061 gradingThe PHY2061 grading•DON’T FORGET TO DO THE DAILY HOMEWORK!!•YOU NEED TO PURCHASE REMOTES FOR THE IN-CLASS QUIZZES (1ST TRIAL ON THURSDAY).•ON-LINE HOMEWORK.PHY 2061 (spring 2005/2006)2 years of 2061:2 years of 2061:20 20 AA(36%)(36%)14 14 B+B+(25%)(25%)11 11 BB(20%)(20%)7 7 CC(13%)(13%)2 2 DD(4%)(4%)Note 82% A/B+/BNote 82% A/B+/BAB+BCDF20 30 40 50 60 70 80 90 10002468Mean = 75%Median = 80%50% of class scored above 80%70% of class scored above 70%Number of studentsScore (%)DO THE HOMEWORK & COME TO CLASSDO THE HOMEWORK & COME TO CLASS•IF YOU ARE HERE ONLY FOR THE GRADE, THE CHANCES ARE HIGH THAT YOU WILL DO POORLY.•THIS IS AN ENRICHED COURSE – YOU ARE HERE TO LEARN.20 30 40 50 60 70 80 90 100 110405060708090100Overall GradeScore on HomeworkPHY 3513 (Fall 2005)••Clear correlation Clear correlation between homework between homework and exam scores.and exam scores.••Nevertheless, the Nevertheless, the exams require exams require understanding, i.e. understanding, i.e. you will not get away you will not get away with memorization of with memorization of homework problems. homework problems.PHY2060 PHY2060 --What causes acceleration?What causes acceleration?Linguistic arguments:Linguistic arguments:••Some sort of interaction Some sort of interaction --loosely speaking, a push or a loosely speaking, a push or a pull on an object.pull on an object.••We call this a We call this a forceforce, which can be said to act on a body., which can be said to act on a body.••Examples of forces:Examples of forces:Normal or "contact force"Normal or "contact force"Gravitational forceGravitational forceElectromagnetic forceElectromagnetic forceWeak and strong nuclear forcesWeak and strong nuclear forcesWe'd better be more We'd better be more scientific about this...scientific about this...The main subject of this courseThe main subject of this courseTest chargeSourcechargesElectrostaticsElectrostaticsLet’s do some experimentsCharges of the same sign repel one another, charges of opposite sign attract one another.What is charge?What is charge?•Charge is measured in Coulomb’s (C)•Fundamental unit.•Definition based on forces between current carrying wires (current = Ampères, or C/s), i.e. chapter 33.•Charge is discrete•Thompson discovered the electron in 1896. He found that charge was carried by elementary particles with the same charge to mass ratio.•The elementary charge of the electron was not measured until 1909 (Millikan).•Both experiments earned Nobel prizes.Charge on an electron: e = 1.6 × 10−19Coulombs1 Coulomb of charge: 6.24 × 1018electrons1 Ampère (= 1 C/s) 6.24 × 1018electrons/secondCharge is discrete: q = ne n = ±1, ±2, ±3,...Static electricity through chargingStatic electricity through chargingConductorConductorInsulatorInsulatorElectrical dischargeElectrical dischargeMethods of charging Methods of chargingCoulombCoulomb’’s Law s Law CoulombCoulomb’’s s torsionaltorsionalbalancebalance178512 1222,or qq qqFFKrr∝=92218.99 10 N m /C4oKπε==×⋅εο= 8.85418781762 × 10-12C2/N·m2()72221410Ns/Cocεπ−=×⋅×c = speed of light in vacuum= 299792458 m/s21ˆ4oqQrπε=FrK““Electrodynamics in a nutshellElectrodynamics in a nutshell””Mix in a little Mix in a little relativityrelativityqQˆroqdε⋅=∫EAGGv0d⋅=∫BAGGvBdddtΦ⋅=−∫EsGGvEoooddidtμμεΦ⋅= +∫BsGGv1212 12 212121221 212211ˆ41ˆ4ooqqrqqrπεπε==−=FrFFrGGG1212 2112ˆˆr==−rrrGCoulombCoulomb’’s Law in vector notation s Law in vector notationSuperposition principleSuperposition principleTest chargeSourcecharges0123...qiii=+++ =∑FFFF F FGGGG G G•Leads to Maxwell’s equations being linear.Calculus (continuous charge distribution):Calculus (continuous charge distribution):ˆˆˆxyzdidFjdF k dF== + +∫∫ ∫ ∫FFGG0214oqdqdFrπε=q0= test
View Full Document
Unlocking...