Course overview

1. Course overview Physics 122, Fall 2012 Lecture I

2. Introduction • Instructor Prof. Regina Demina • Office B&L 367 • Phone 275-7357 • Email profdemina@gmail.com • Office hour Mon 3-4 pm Lecture I

3. Novosibirsk Lecture I

4. Objective of the course • thorough understanding of the basic physics concepts • ability to use them in applications Lecture I

5. Sources • Text book Physics for Scientists and Engineers, Volume II Forth Edition by Douglas C. Giancoli • Class web site /www.pas.rochester.edu/~regina/PHY122 • Lecture notes; • Homework assignments • Workshop modules • Equation sheets for tests, test solutions • Important dates and links Lecture I

6. Solving problems systematically is important. Peer-lead study groups – workshops Participation in workshops will count 5% of your final grade. Workshops start next week Participation in workshops = 5% of your final grade, need to participate (not just attend!) in at least 10 workshops to get full grade. Homework problems are similar but not identical to workshop modules Homework problems = 5% of your final grade. Questions on workshop scheduling: "Dev Ashish Khaitan" <dkhaitan@u.rochester.edu> Workshops and Homework Lecture I

7. Midterm exams • There will be two midterm exams during the semester. • Both will count. • There will be no makeup exam. • You can bring a calculator, a pencil and a ruler. • 40% of your grade. Lecture I

8. Final Exam • December 17, 7:15 pm • Final exam is based on the entire course PHY122. • Last homework will be based on the entire course to give you more time to prepare for the final. • 40% of the final grade Lecture I

9. Equation sheets • No notes or equation sheets may be brought to exams. • However, a sheet of useful equations will be provided during the test. You can view these sheets in advance, will be linked from course schedule on the web. • Please note that past experience has shown that having equations available does not guarantee success -- understanding is the key. Lecture I

10. Labs • The laboratory is a required and integrated part of the course. • A passing grade in laboratory is required to pass the course: 10% of the grade • Questions should go to physlabs@pas.rochester.edu • NB. I am not allowed to reveal this person’s identity. Lecture I

11. Grading • Workshops: 5% • Homework: 5% • Hour Exams: 40% • Final Exam: 40% • Laboratory: 10% • Total: 100% • 90% or above: A 88-89.9 – A- 85-87.9 – B+ • 80% - 85% : B 78-79.9 – B- 75-77.9 – C+ • 70% - 75%: C 68-69.9 – C- 65-67.9 – D+ • 60% - 65%: D • Under 60% : E Lecture I

12. PHY122 too easy?You still have a chance to switch to PHY142 Lecture I

13. How to study for physics class • Look through lecture notes first • In lectures I’ll give you all the information that you need to survive in this class • Read the suggested sections from the text book • Read the summary first – concentrate on what’s important • Don’t overdo the reading part, try to understand not memorize • Pay attention to • Figures, spend more time on them than on text • Examples, try to work out the problem yourself first • Equations (try to analyze, e.g. if the charge doubles the Coulomb force on it will double as well) Lecture I

14. How to do physics problems • Use the “How to do physics problems” guide posted on the course web site • While doing first several homework assignments and workshop modules stick to it religiously • This practice will help you during the tests • PHY122 is a lot more abstract than PHY121 – well developed procedures will help you to get started Lecture I

15. PHY 121 • Kinematics – how do objects move? • Trajectory, displacement, velocity, acceleration, time • Dynamics – why do objects move? • Mass, force work • Conserved quantities • Energy – potential and kinetic • Momentum • First step into micro world – kinetic theory • Mechanical laws work on molecules • Heat is a form of energy Lecture I

16. PHY 122 • What is the origin of forces? • So far we considered only one true force – gravity • Next step – electricity and magnetism • Static – new conserving quantity – electric charge • Dynamic – DC and AC • Magnetic field • Electromagnetic waves – light Lecture I

17. Phases of matter • Solid, liquid, gas Matter is built of atoms Lecture I

18. Inside atoms • Atoms have structure = nucleus + electrons • Nucleus has positive electric charge • Electron has negative electric charge • Nucleus has structure = protons and neutrons • Electron so far is believed to be elementary = unbreakable Lecture I

19. Inside nucleus • Protons and neutrons consist of quarks, called up and down quarks • Quarks are believed to be elementary Lecture I

20. Nature’s scales Antimatter Lecture I

21. My research - LHC Alps • Large Hadron Collider located in Europe (France and Switzerland) • Circumference 27 km; • 7TeV(2010-2011)8TeV (now)14 Tev(2014) • LHC has uncovered the mechanism behind mass - 2012 • Discovery of particle known as Higgs boson • Prof Hagen (Rochester) – one of the six people who predicted this mechanism Lecture I

22. Hgg Lecture XII

23. HZZ*4l Lecture XII

24. Electricity • There are two kinds of electric charges – positive and negative. • Like charges (++, or --) repel, • unlike charges (+-) attract. Lecture I

25. Inside atoms • Atoms have structure = nucleus + electrons • Nucleus has positive electric charge • Electron has negative electric charge (Q= -e) • Nucleus = protons (Q=+e) and neutrons (Q=0) Electrons are much lighter and thus more mobile than protons or neutrons. Lecture I

26. The net charge is conserved. Electric charge is measured in Coulombs. Electron has negative charge (e=-1.60.10-19 C), nucleus – positive. Atom is electrically neutral. Nucleus is heavy, electron is light. Usually charge is transported by electrons. By acquiring more electrons bodies become negatively charged (Q= -Ne .e) By loosing electrons bodies become positively charged (Q= +Ne .e). Electric charge Lecture I

27. Insulators and conductors • In solids atoms and their nuclei are “locked” in their position and hard to move. • Insulators have complete or almost complete electron shells – these electrons are tough to move around. • Conductors (usually metals) have one or two electrons on the outer shell – “free” electrons. Lecture I

28. Induced charge Bodies can be charged by • Conduction (direct contact) • Induction – create charge separation • Break into pieces • “Ground“one end – charge leaks into the Earth. Always think, where electrons went – they are the ones to move. Lecture I

29. Electroscope Electroscope – asimple device to detect electric charge. Lecture I

30. Test problem #1 • Two electrically neutral materials are rubbed together. One acquires a net positive charge. The other must • A have lost electrons. • B have gained electrons. • C have lost protons. • D have gained protons. Lecture I

31. F – force between two charges(N) Q – electric charge (C= Coulomb) r – distance between the two charges (m) k – constant Coulomb’s law + + 1 2 + - 1 2 Lecture I

32. System of charges Calculate the net electrostatic force on particle 3. Input: • Q1= - 86mC= - 86.10-6 C • Q2= + 50mC= + 50.10-6 C • Q3= + 65mC= + 65.10-6 C • r13=60cm=0.60m • r23=30cm=0.30m Lecture I

33. This week • Sign up for workshops if you have not done so. • Workshops start next week. Lecture I

34. My research – getting inside atoms • Fermilab • 40 miles west of Chicago • Tevatron – at the moment world’s 2nd highest energy collider • 2 teraelectronvolts • 6.28 km circumference • Top quark discovery - 1996 Lecture I