PHY 113 C General Physics I 11 AM12

PHY 113 C General Physics I 11 AM-12: 15 PM TR Olin 101 Plan for Lecture 1: 1. Welcome & overview 2. Class structure & announcements 3. Chapter 1 – measurement & units 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 1

PHY 113 A General Physics I 11 AM-12: 15 PM TR Olin 101 Instructor: Natalie Holzwarth (Olin 300) Course Webpage: http: //www. wfu. edu/~natalie/f 13 phy 113 Text: Physics for Scientists and Engineers with Modern Physics by Serwey and Jewett, 9 th edition* Webpage for Webassign system: http: //www. webassign. net/ You will also need an i-clicker device for each class A scientific calculator will be needed for homework and exams --------*May replace with used texts including 8 th edition versions. 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 2

Where to find information about the course on the web: http: //users. wfu. edu/natalie/f 13 phy 113 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 3

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Comment about Physics Colloquia 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 5

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Course organization: http: //users. wfu. edu/natalie/f 13 phy 113/info/ 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 7

http: //users. wfu. edu/natalie/f 13 phy 113/homework/ 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 8

www. webassign. net Username = wfu email ID (without @wfu. edu) Institution = wfu Password = PHYSICSROCKS (change ASAP) 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 9

www. webassign. net 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 10

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W=63 ft Problem solving steps 1. Visualize problem – labeling variables 2. Determine which basic physical principle(s) apply 3. Write down the appropriate equations using the variables defined in step 1. 4. Check whether you have the correct amount of information to solve the problem (same number of knowns and unknowns). 5. Solve the equations. 6. Check whether your answer makes sense (units, order of magnitude, etc. ). 8/27/2013 L=111 ft area = width * length A=W*L OK PHY 113 A Fall 2013 -- Lecture 1 13

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i>clicker exercises: Which of the following options do you prefer for the number of exams in the course? A. 3 exams B. 2 exams Which of the following options do you prefer for the exam times? A. Exams within class time (75 minutes) B. Exams offered outside of class time 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 15

i>clicker exercise: Preferences for tutorial times: A. 5: 30 -7: 30 PM B. 6 -8 PM C. 7 -9 PM D. 8 -10 PM E. Other 8/27/2013 (Sunday – Thursday) PHY 113 A Fall 2013 -- Lecture 1 16

PHY 113 Labs will start Monday Sept. 3 rd and run through the week of Nov. 16 th. There will be no labs during Thanksgiving week. PHY 113 Tutorial sessions will also start next week. 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 17

General advice on how to learn physics: Ø Physics is built on basic principles (“laws”) from which all results can be derived (deduced) Ø Focus your attention on understanding the basic principles Ø Practice using these basic principles to solve problems Ø Memorization is of little use in the study and practice of physics Note: In general, the best way to learn physics is to practice problem solving. One benefit of learning physics is the development of general problem solving skills. Note that memorization of the text and lecture material is rarely useful. As you are working problems, you may wish to construct a sheet of paper containing the basic equations you use. This basic equation sheet (8. 5 in x 11 in) can be used during exams. 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 18

Problem solving skills Math skills Equation Sheet Advice: 1. Keep basic concepts and equations at the top of your head. 2. Practice problem solving and math skills 3. Develop an equation sheet that you can consult. 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 19

Problem solving steps 1. Visualize problem – labeling variables 2. Determine which basic physical principle(s) apply 3. Write down the appropriate equations using the variables defined in step 1. 4. Check whether you have the correct amount of information to solve the problem (same number of knowns and unknowns). 5. Solve the equations. 6. Check whether your answer makes sense (units, order of magnitude, etc. ). 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 20

The Zeroth Law of Physics y (m) All physical phenomena can be analyzed using fundamental “laws” which are stated in terms of basic concepts and represented in terms of mathematical expressions and equations. 8/27/2013 x--(m) PHY 113 A Fall 2013 Lecture 1 21

i>clicker exercise: Why would a physicist (or anyone else) want to know that the ball follows a parabolic trajectory? A. Because it tests the basic principles of physics. B. Because it can help a golfer get a hole in one. C. Because it shows that gravity is effecting the motion of the ball. D. Because it shows a contrast with straight line motion. E. Because it makes you look smart. 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 22

The Zeroth Law of Physics All physical phenomena can be analyzed using fundamental “laws” which are stated in terms of basic concepts and represented in terms of mathematical expressions and equations. In order to perform the analysis, it is necessary to have standard units to measure the quantities of interest – time, distance, mass, etc. 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 23

Measurement units Standard units “SI” (by international agreement in 1960) length – meter mass -- kilogram time -- second 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 24

http: //www. nist. gov/pml/wmd/metric/length. cfm 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 25

http: //www. nist. gov/pml/wmd/metric/mass. cfm 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 26

http: //www. nist. gov/pml/wmd/metric/time. cfm 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 27

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Terrible example: 8/27/2013 1012 bull PHY 113 A Fall 2013 -- Lecture 1 30

Comments about errors in measurement 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 31

Comments about errors in measurement -- continued i>clicker exercise: What should we do about this? A. Leave it as is? B. Expand the expression? C. Run away screaming? 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 32

Comments about errors in measurement -- continued 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 33

Comments about errors in measurement -- continued 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 34

Comment on significant figures In my opinion the notion of significant figures is more trouble than it is worth and is given more ink (pixels) than it deserves. If you are performing a calculation, NEVER round your answer except possibly after the last step. 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 35

Reminders • Contact me (Olin 300, x 5510, natalie@wfu. edu) with any questions, concerns, etc. • Before next class: skim Chapter 1 and read Chapter 2 of textbook; Email natalie@wfu. edu with a question concerning one-dimensional motion • Try practice problems in webassign. net (Assignment 1) • Bring i>clickers to class 8/27/2013 PHY 113 A Fall 2013 -- Lecture 1 36