Physics 114 – General Physics II

1. Everyone Pick Up: • Syllabus • Student Info sheet – fill it out Materials • Physics for Scientists and Engineers, 9th ed., Serway and Jewett, with webassign, through chap. 39 • Scientific Calculator* • iclicker* • Laptop • 30 cm metric ruler * - bring these to class Physics 114 – General Physics II Eric Carlson “Eric” “Professor Carlson” Olin 306 Office Hours always 758-4994 (o) 407-6528 (c) ecarlson@wfu.edu Topics Covered: • 30% Electricity • 30% Magnetism • 30% Optics • 10% Modern Physics http://www.webassign.net/student.html http://users.wfu.edu/ecarlson/phy114 1/15

2. Can I add This Section? • This class has a capacity of 50 students, with 54 enrolled • To get my permission to add, you must: • Have a pretty good case that you need to take PHY 114 now • Have an ironclad case that you can’t get into the other two sections PHY 114 Sections Spring 2014 Sec.EnrolledMeetsProfessor A 45/50 TR 9:30 – 10:45 Cook B 50/50 MWF 11:00 – 11:50 Dostal C 54/50 MWF 10:00 – 10:50 Carlson

3. Dr. Carlson’s Schedule Monday Tuesday Wednesday Thursday Friday 9:00 10:00 research PHY 114 PHY 114 PHY 114 11:00 PHY 742 PHY 742 PHY 742 12:00 office hour office hour office hour 1:00 officehours officehours 2:00 research research research 3:00 research Free food 4:00 colloquium 5:00

4. Preparing for Lecture Reading Assignment • Sections 23.1 – 23.3 by Friday • Sections 23.4 – 23.6 by Wednesday Quizzes: • Reading quiz 23a by Friday • Reading quiz 23b by Wednesday • Read the material assigned on the Web, or in class each day, before class starts • Take a webassign-based reading quiz online by 9:30 AM • You only get one chance to answer these questions http://www.webassign.net/student.html

5. Class attendance, Seating, Participation • I do not grade directly on attendance • But it is basically necessary for class participation • I will be taking attendance, usually • Starting Wednesday, everyone will sit in the same seat every day (your choice which seat) • Not the back row Do you understand how concept iclicker questions work? A) Yes, I’ve done it before B) Yes, though it’s new to me C) Sort of, I’ll figure it out D) Huh? Class Participation Grade and the iclicker • I present a multiple choice question • Round 1 – You must figure out or guess the answer,then vote with your iclicker • You discuss the questions with your classmates • Round 2 – You get a second chance to get the answer right • Right answers: 4/4, wrong answers: 3/4 • If you get 80% or more, you get full credit on class participation • Participating in class discussion gains bonus points that can push up your participation grade, even past full credit

6. Homework and webassign http://www.webassign.net/student.html • All homework is on webassign • Bookstore can sell you a license, or you can get it online • Personalized problems, you need to get correct to 1% or better • Handout about webassign is on the class web page • Due almost every class day at 9:30 AM • Personalized problems – you can’t copy • Eight chances to get it right • Getting help is encouraged • Ask a friend, ask me, come to office hours • First assignment is due on Wednesday of next week

7. Exams Exam Dates: February 10 March 7 April 9 May 2, 9 AM • 3 tests and a final • Honors code violations will be turned in to thehonor council • Normally, penalty is 1-term suspension andan irreplaceable F in the course • Multiple choice, short essay and computational problems • If ill, call me/email me immediately or bring a Doctor’s note Red dashed line means you should be able to use this on a test, but you needn’t memorize it Red boxes mean memorize this for the test Other colors mean not on the test Dotted red means easily derived from other formulas

8. Miscellaneous The Web Labs Numerous materials can be found on the web for this course • These lectures • Math review • Syllabus and other handouts • Reading assignments and quizzes • Test information • You are required to sign up for PHY 114L • You must pass the lab to pass the class • Labs begin on January 27 Pandemic Plans • If there is a catastrophic closing of the university, we will attempt to continue the class: http://users.wfu.edu/ecarlson/phy114 Emergency contacts: Web page email Cell: 336-407-6528

9. Grades Percentage Breakdown: Test 1 12% Test 2 12% Test 3 12% Final 24% Homework 20% Lab 10% Class Part. 5% Read Quiz 5% Grade Assigned 94% A 73% C 90% A- 70% C- 87% B+ 67% D+ 83% B 63% D 80% B- 60% D- 77% C+ <60% F • Little if any curving • Do not allow extra credit

10. Background Information Prerequisites • Physics: PHY 113 (or 111), mechanics, etc. • You should have a good understanding of basic physics • Be familiar with units and keeping track of them, scientific notation • Should know key elementary formulas like F = ma • Mathematics: MTH 111, introductory calculus • Know how to perform derivatives of any function • Understand definite and indefinite integration • Work with vectors either abstractly or in coordinates • There is a math review online with everything you need to know

11. SI Units Fundamental units Time second s Distance meter m Mass kilogram kg Temperature Kelvin K Charge Coulomb C Red boxes mean memorize this, not just here, but always! Derived units Force Newtons N kgm/s2 Energy Joule J Nm Power Watt W J/s Frequency Hertz Hz s-1 Elec. Potential Volt V J/C Capacitance Farad F C/V Current Ampere A C/s Resistance Ohm  V/A Mag. Field Tesla T Ns/C/m Magnetic Flux Weber Wb Tm2 Inductance Henry H Vs/A Metric Prefixes 109 G Giga- 106 M Mega- 103 k kilo- 1 10-3 m milli- 10-6 micro- 10-9 n nano- 10-12 p pico- 10-15 f femto-

12. Vectors • A scalar is a quantity that has a magnitude, but no direction • Mass, time, temperature, distance • In a book, denoted by math italic font • A vector is a quantity that has both a magnitude and a direction • Displacement, velocity, acceleration • In books, usually denoted by bold face • When written, usually draw an arrow over it • In three dimensions, any vector can be describedin terms of its components • Denoted by a subscript x, y, z • The magnitude of a vector is how long it is • Denoted by absolute value symbol, orsame variable in math italic font z y vx vz vy x

13. Finding Components of Vectors • If we have a vector in two dimensions, it is pretty easy to compute its components from its magnitude and direction y v vy • We can go the other way as well vx x • In three dimensions it is harder

14. Unit Vectors • We can make a unit vector out of any vector • Denoted by putting a hat over the vector • It points in the same direction as the original vector • The unit vectors in the x-, y- and z-direction are very useful – they are given their own names • i-hat, j-hat, and k-hat respectively • Often convenient to write arbitrary vector in terms of these

15. Adding and Subtracting Vectors • To graphically add two vectors, just connect them head to tail • To add them in components, just add each component • Subtraction can be done the same way

16. Multiplying Vectors There are two ways to multiply two vectors • The dot product produces a scalar quantity • It has no direction • It can be pretty easily computed from geometry • It can be easily computed from components • The cross product produces a vector quantity • It is perpendicular to both vectors • Requires the right-hand rule • Its magnitude can be easily computed from geometry • It is a bit of a pain to compute from components