PHY 113 A Fall 2013 -- Lecture 1 18/27/2013
PHY 113 C General Physics I11 AM-12:15 PM TR Olin 101
Plan for Lecture 1:
1. Welcome & overview2. Class structure & announcements3. Chapter 1 – measurement & units
PHY 113 A Fall 2013 -- Lecture 1 28/27/2013
PHY 113 A General Physics I11 AM-12:15 PM TR Olin 101
Instructor: Natalie Holzwarth (Olin 300)Course Webpage: http://www.wfu.edu/~natalie/f13phy113
Text: Physics for Scientists and Engineers with Modern Physics by Serwey and Jewett, 9th edition*
Webpage for Webassign system:http://www.webassign.net/
You will also need ani-clicker device for each class
A scientific calculator will be needed for homework and exams----------------*May replace with used texts including 8th edition versions.
PHY 113 A Fall 2013 -- Lecture 1 38/27/2013
Where to find information about the course on the web: http://users.wfu.edu/natalie/f13phy113
PHY 113 A Fall 2013 -- Lecture 1 48/27/2013
PHY 113 A Fall 2013 -- Lecture 1 58/27/2013
Comment about Physics Colloquia
PHY 113 A Fall 2013 -- Lecture 1 68/27/2013
PHY 113 A Fall 2013 -- Lecture 1 78/27/2013
Course organization: http://users.wfu.edu/natalie/f13phy113/info/
PHY 113 A Fall 2013 -- Lecture 1 88/27/2013
http://users.wfu.edu/natalie/f13phy113/homework/
PHY 113 A Fall 2013 -- Lecture 1 98/27/2013
www.webassign.net
Username = wfu email ID (without @wfu.edu)Institution = wfuPassword = PHYSICSROCKS (change ASAP)
PHY 113 A Fall 2013 -- Lecture 1 118/27/2013
PHY 113 A Fall 2013 -- Lecture 1 128/27/2013
PHY 113 A Fall 2013 -- Lecture 1 138/27/2013
Problem solving steps1. Visualize problem – labeling
variables2. Determine which basic physical
principle(s) apply3. 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.).
L=111 ft
W=63 ft
area = width * length
A = W * L
OK
2
2
m 649.2 ft 3.282
m 1ft 111 ft 63
A
PHY 113 A Fall 2013 -- Lecture 1 148/27/2013
sst
VRa gal/ 0.033 min/ 60 min 5
gal 10 )
PHY 113 A Fall 2013 -- Lecture 1 158/27/2013
i>clicker exercises:
Which of the following options do you prefer for the number of exams in the course?
A. 3 examsB. 2 exams
Which of the following options do you prefer for the exam times?
C. Exams within class time (75 minutes)D. Exams offered outside of class time
PHY 113 A Fall 2013 -- Lecture 1 168/27/2013
i>clicker exercise:
Preferences for tutorial times: (Sunday – Thursday) A. 5:30-7:30 PM B. 6-8 PM C. 7-9 PM D. 8-10 PM E. Other
PHY 113 A Fall 2013 -- Lecture 1 178/27/2013
PHY 113 Labs will start Monday Sept. 3rd and run through the week of Nov. 16th. There will be no labs during Thanksgiving week.
PHY 113 Tutorial sessions will also start next week.
PHY 113 A Fall 2013 -- Lecture 1 188/27/2013
General advice on how to learn physics:
Physics is built on basic principles (“laws”) from which all results can be derived (deduced)
Focus your attention on understanding the basic principles Practice using these basic principles to solve problems 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.
PHY 113 A Fall 2013 -- Lecture 1 19
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.
Equation Sheet
dtddtdm
rv
va
aF
Problem solving skills
Math skills
8/27/2013
PHY 113 A Fall 2013 -- Lecture 1 20
Problem solving steps
1. Visualize problem – labeling variables2. Determine which basic physical principle(s) apply3. 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 21
y (m
)
x (m)8/27/2013
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.
PHY 113 A Fall 2013 -- Lecture 1 228/27/2013
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.
PHY 113 A Fall 2013 -- Lecture 1 238/27/2013
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.
PHY 113 A Fall 2013 -- Lecture 1 248/27/2013
Measurement units
Standard units “SI” (by international agreement in 1960) length – meter mass -- kilogram time -- second
PHY 113 A Fall 2013 -- Lecture 1 258/27/2013
http://www.nist.gov/pml/wmd/metric/length.cfm
PHY 113 A Fall 2013 -- Lecture 1 268/27/2013
http://www.nist.gov/pml/wmd/metric/mass.cfm
PHY 113 A Fall 2013 -- Lecture 1 278/27/2013
http://www.nist.gov/pml/wmd/metric/time.cfm
PHY 113 A Fall 2013 -- Lecture 1 288/27/2013
PHY 113 A Fall 2013 -- Lecture 1 298/27/2013
PHY 113 A Fall 2013 -- Lecture 1 308/27/2013
Terrible example: 1012 bull
PHY 113 A Fall 2013 -- Lecture 1 318/27/2013
Comments about errors in measurement cm 1.03
cm 3.1 cm 2.9 cm 1.03
PHY 113 A Fall 2013 -- Lecture 1 328/27/2013
Comments about errors in measurement -- continued
cm 1.03L
cm 1.02w
cm 1.03cm 1.02 area wLA
i>clicker exercise:What should we do about this?A. Leave it as is?B. Expand the expression?C. Run away screaming?
PHY 113 A Fall 2013 -- Lecture 1 338/27/2013
Comments about errors in measurement -- continued
cm 1.03L
cm 1.02w
cm 1.03cm 1.02 area wLA
cm 0.5 6
cm 01.0 3.0 2.0 6
cm1.01.031.01.0232
cm 1.03cm 1.02
2
2
2
wLA
PHY 113 A Fall 2013 -- Lecture 1 348/27/2013
Comments about errors in measurement -- continued
cm 1.03L
cm 1.02w
cm 1.03cm 1.02 area wLA
ww
LL
AA
ww
LL
AA
LwwLwLLwLw
AAA
wLwLLwLwLwLLAA
11
:calculus and algebra simple Using
08333.021.0
31.0 :caseour In
AA
PHY 113 A Fall 2013 -- Lecture 1 358/27/2013
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.
kg 3.03.7report toreasonable be It wouldkg 621.7 M kg 021.7 that means This
kg 3.0321.7 measureyou Suppose :Example
MM
MM
PHY 113 A Fall 2013 -- Lecture 1 368/27/2013
Reminders • Contact me (Olin 300, x5510, [email protected])
with any questions, concerns, etc.• Before next class: skim Chapter 1 and read
Chapter 2 of textbook; Email [email protected] with a question concerning one-dimensional motion
• Try practice problems in webassign.net (Assignment 1)
• Bring i>clickers to class