1. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Welcome to Physics I !!! Prof. Wasserman LECTURE 1

2. Department of Physics and Applied Physics 95.141, F2009, Lecture 1

3. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Outline Why Physics? Course organization Course grading Chapter 1 –Significant figures –Units –Estimating

4. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Why Physics? Students in this course come from diverse backgrounds and are heading in diverse directions Physics provides all with a scientific toolbox –Physics describes the fundamental operation of the world around us: Engineering, Chemistry, Biology, Astronomy, etc. –Teaches us how to approach complex problems Science is inherently progressive –If approached correctly, we can all contribute! What you are going to do matters!

5. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Physicists look at the world differently This class will attempt to show you how we understand the world around us

6. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Course Organization Everything you need to know about the course can be found on the course website: http://faculty.uml.edu/dwasserman/95.141.htm http://faculty.uml.edu/dwasserman/95.141.htm

7. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Course Communication Website –http://faculty.uml.edu/dwasserman/95.141.htmhttp://faculty.uml.edu/dwasserman/95.141.htm Physics I Twitter account: @UMLPhysicsIS10 On Facebook, search for "UML Physics I S2010"

8. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Course Organization Physics I meets 4 times a week –Lectures 2:30-3:20 MW, OH 150 –Recitation Sections Varying times, locations Know your instructor and section number!!! –Homework review sessions 6:30-9:30 pm, OH 218 Held every week before HW is due Textbook: Giancoli: Physics for Scientists and Engineers, 4 th Ed. NO LAB THIS WEEK!! RECITATION SECTIONS THIS WEEK!!

9. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Lecture Organization Exam Prep. Problem Review of Previous Lecture Lecture Main Topic –Will include clicker questions –Example problems Symbolic Numerical –Movie clips –Demonstrations Summary LECTURES MOVE FAST!!!

10. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Lectures NO COMPUTERS IN LECTURE!! NO CELL PHONES!! NO TALKING!!

11. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Recitation Section Organization Lecture Summary Example problems from Book Quizzes

12. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Course Grading ItemPoints Standard HW90 LP HW20 Quizzes90 Participation30 Exam 020 Exam 1100 Exam 2100 Exam 3100 Final Exam200 Total750 RangeGrade >600A 560-599B+/A- 490-559B 450-489C+/B- 375-449C 340-374D+/C- 265-340D <265F

13. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 PRS Clickers For detailed info on setting up PRS clickers, go to: http://clickers.wiki.uml.edu/Student+Resources http://clickers.wiki.uml.edu/Student+Resources You must have your own clicker!! –You cannot borrow a friend’s clicker for class –You may not have more than 1 clicker in class: this is academic fraud. Clickers will be used to determine part of participation grade

14. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Let’s Set-Up Our PRS Clickers A.Power on your clicker B.When autoscan begins, press * to stop it C.Press * to display the Setup Menu D.Scroll up to display the ID: menu option E.Press enter (green arrow) to select it F.Input your Student ID: No Alpha Characters, No Leading Zeros!!! Press the left arrow to backspace if you make an error G. If correct, press enter (green arrow) to save your Student ID H. You may shut off the PRS or Press * and enter (green arrow) to scan for classes

15. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 PRS Example Enter class letter (or number): then “enter” Question: In order to do well in Physics I, you should spend how many hours working on Physics I material for every hour in class (recitation and lecture)? –A) 0-1 HRS –B) 1-2 HRS –C) 2-3 HRS –D) 3+ HRS

16. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Standard Homeworks Homework assignments online at course website (http://faculty.uml.edu/dwasserman/95.141.htm) Most weeks, the written HW is due on Friday (there are 2 weeks when the HW is due Wed.). There will be a box in the Physics front office where you can turn your HWs in. HWs will be returned in section within ~1 week. HWs must have NAME and SECTION # !!! Please follow the HW guidelines in the syllabus. Graded out of 10, total 90/750 of your final grade Late homeworks not accepted. Homework review sessions for EVERY homework set.

17. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Lecture Prep Homeworks These HWs are designed as review of the previous lecture, and are due before each lecture. Usually consist of 2-3 tutorials. You have unlimited attempts to answer. Use these as a study guide to keep you up to speed with lectures. Count for 20 pts over the course of the semester DONE ONLINE!!!! www.masteringphysics.com –Course “WASSERMANS10” Instructions can be found on website for accessing masteringphysics.com

18. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 www.masteringphysics.com

19. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 www.masteringphysics.com

20. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Quizzes Given by recitation instructor, during recitation. 90/750 of Final Grade. No remakes. (for excused absences, recitation instructor can drop missed quiz). Normalized to class quiz average (a tough recitation instructor doesn’t hurt your final grade!) Should cover material from previous week’s class/recitation.

21. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 EXAMS 3 Mid-Term Exams –Each worth 100 pts. –Taken in class. –Each covers lectures from previous exam up to exam date –No rescheduling –Extra time available for students with disabilities (must have note from Office of Student Disabilities) Final Exam –200 pts. –Date/Time/Location To Be Announced

22. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 EXAM 0 There will be an Exam 0 in class on Wednesday. Exam 0 counts for 20 pts. This is a test of very basic math skills and the contents of Lecture 1 and Chapter 1. This is meant to be a tool for you It will give you a chance to see where your quantitative skills stand, to see whether you are prepared for this very challenging course. The difficulty level of Exam 0 is not indicative of the types of exams I give!!

23. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Physics I Resources Need to get help as soon as you feel like you may be falling behind! The first person to contact if you are having problems with Physics I is your Recitation Instructor!! Recitation Instructors will have office hours each week during which they can meet. HW review sessions UML tutoring center: information on course website (http://faculty.uml.edu/dwasserman/95.141.htm)

24. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Fun ≠ Easy We have worked very hard to make this course fun and interesting! But this does not mean the course will be easy. This stuff matters!! 1hr in class = 3+ hrs outside of class You will have to work hard to do well in Physics I. You will have to be organized to do well in Physics I. You will have to come to class to do well in Physcis I.

25. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Physics I (95.141) Lecture 0: Online Basic Trig., Calc. and other mathematical concepts. Lecture 1: Chapter 1

26. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Chapter 1-3: Measurement and Uncertainty No measurement is perfectly precise –For any measurement, it is important to give the uncertainty in the measurement Either in absolute numbers: 0.1g or 0.2mm, for example Or in percentage: 10m +/- 2%, or 3.2kg +/- 10%

27. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Chapter 1-3: Measurement and Uncertainty If uncertainty is not explicitly mentioned, we assume it to be 1, or a few units in the last digit specified –“The speed of the car was 51.2 mph” Means… –“The speed of the car was 51.2 mph +/- ~0.1mph”

28. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Significant Figures Significant figures: the number of reliably known digits in a number –45.21 kg  4 significant figures –0.00495m  3 significant figures If you are making a measurement, be careful about how many digits you use!! –i.e. I am 6 ft 4.23457 inches Scientific Notation –4,560,000,000  4.56 x 10 9

29. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Chapter 1-4: Units Units are important!!! If I am bragging about my weight: –“I weigh 150!” Could mean: –“I weigh 150lbs” Or…. –“I weigh 150kgs” In Physics we try to use the same set of units: SI: Système Internationale

30. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Chapter 1-4: SI Units Length: meters [m] Time: seconds [s] Mass: kilogram [kg] Temperature [K] For dealing with very small or very large numbers, we can make use of prefixes: G  giga  10 9 M  mega  10 6 K  kilo  10 3 m  milli  10 -3 µ  micro  10 -6 n  nano  10 -9 100,000m can also be written as 100 kilometers (km) 0.0001s could be written as 100 microseconds (µs)

31. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Chapter 1-4: Converting Units Sometimes we don’t get problems in the units we like… –Two cars are traveling on the highway, car 1 at 55mph, car 2 travels 200m in 10s. Which is going faster? –Need to convert between mph and m/s  conversion factor –Car 1 –Car 2

32. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Chapter 1-6: Estimating Why is estimating important?

33. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Chapter 1-6: Estimating Being able to make order of magnitude estimates is an important skill!!

34. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Chapter 1-6: Estimating (Fermi Problems) What is the capacity of this room? Could try to count every chair Or could make a quick estimate…

35. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 How many barbers/salons should a town of 300,000 people have? Chapter 1-6: Estimating (Fermi Problems)

36. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Chapter 1-7: Dimensional Analysis Dimensions of a quantity refer to the units that make it up –Speed  L/T, i.e. [m/s] –Acceleration  L/T 2, i.e. [m/s 2 ] We can learn a lot simply by looking at the units involved in an expression. If someone tells you that the speed of a car is given by the following expression:

37. Department of Physics and Applied Physics 95.141, F2009, Lecture 1 Chapter 1-7: Dimensional Analysis Later in the semester, we will learn that Force has the units of Newtons [N] F=ma F g =GM 1 M 2 /R 2 What are the Units of G-Universal Gravitational Constant?