1. Welcome to PHYSICS 220 (Section 2)
Prof. Yulia Pushkar
Kinematics
Forces
Energy and Momentum
Rotations
Fluids
Oscillations/Waves/Sound
Thermodynamics
Lecture 1
Purdue University, Physics 220

2. Purdue University, Physics 220
Textbook
The textbook is College Physics, Vol I, by Nicholas J. Giordano (Brooks/Cole).
We will cover almost all of the topics in this volume, at a rate of one chapter per week!
Very Fast!
Come prepared!
Lecture 1
Purdue University, Physics 220

3. Purdue University, Physics 220
Course Web Site
Course Syllabus
Policies
Grading scheme
Exams & iClicker exercises
Lab Syllabus
Tentative Class Calendar
Pre-lecture reading assignments
Homework due dates
CHIP User’s Guide
Homework
Grades
Lecture 1
Purdue University, Physics 220

4. Purdue University, Physics 220
Class Format
Lecture Section 2:
Time: Monday, Wednesday 11: :20
Lecture Room: PHYS 114
Instructors: Prof. Yulia Pushkar
Office Hours: 12:30 am – 1:30 pm on Monday and Wednesday
Office: PHYS Phone:
(please include on the subject line: PHYS 220)
Recitation Section 2:
Time: Friday 11: :20
Instructor: Deepak Pandey Office Hours: Friday: 12:30 AM - 5:30 PM
Office: PHYS 11A Phone:
CHIP coordinator: Dr. V.K. Saxena, PHYS 176
Laboratory:
Coordinator: Dr. A. Lewicki, Office: PHYS 142
Lab Room: PHYS 121
Lecture 1
Purdue University, Physics 220

5. Purdue University, Physics 220
Homework
We will use CHIP (Computerized Homework In Physics) for homework assignments
The homework is due by 10 am on Fridays
Homework is computer graded
100% if completed before the deadline
75% if completed within three days of the deadline
50% if completed after three days but within one week of the deadline
0% after one week past the deadline
There is a limit on the number of attempts allowed.
Lecture 1
Purdue University, Physics 220

6. Purdue University, Physics 220
iClicker
We will use iClicker for interactive lecture and recitation exercises
One point for participating in each exercise
Two points for each correct answer
iClicker can be purchased at the Purdue bookstore
Registration:
You must register your iClicker on CHIP!
Use serial number at the back of your iClicker
Go to CHIP -> Student Gradebook
DO NOT register on the iClicker web site!
Deadline: by the end of this week
We will start to use iClicker next week!
Lecture 1
Purdue University, Physics 220

7. Purdue University, Physics 220
Exams and Grades
Exams:
There will be two midterm exams and one final exam. All exams are closed-book. The final exam will be cumulative.
Exam 1: Feb 22, 2010, 6:30 – 7:30 PM
Exam 2: Mar 29, 2009, 6:30 – 7:30 PM
Final: TBA (2 hours)
Grades:
The final grade will be determined on the following basis:
300 points final exam
300 points two evening exams (150 points each)
150 points laboratory
100 points CHIP homework
50 points recitation exercises
100 points lecture exercises
No excused iClicker exercises.
You must pass the lab in order to pass the course.
Lecture 1
Purdue University, Physics 220

8. Purdue University, Physics 220
Tips
Pre-lecture reading
Come to the lectures prepared!
Things to pay attention to
Concepts, connections, motivation: Lecture
Problem solving: Recitation + Homework
Hands-on lab
Taking notes
Lecture notes can be downloaded from the course web site
But they are sketchy … you need to fill in details in class
Post-lecture reading
See if there are still things you do not understand
Seeking help
See us during office hours!
Physics Help Center
Lecture 1
Purdue University, Physics 220

9. Why it is cool to study Physics?
The science of matter and energy, and the interactions between them
Matter and energy are fundamental to all areas of science
The study of the natural or material world and phenomena
Meaning of physics from the Greek for Nature
Natural philosophy
Oldest science
All scientists were originally physicists

10. Purdue University, Physics 220
About Me
Biophysics:
From Photosynthesis to future energy solutions
Imaging metals in the brain with X-ray techniques
Want to learn more? Visit
Lecture 1
Purdue University, Physics 220

11. Types of Problems We will encounter various types of problems
Quantitative problems
Give numerical information and use calculations
Concept checks
Test your general understanding of a law and its application
Reasoning and relationship problems
Indentify what important information might be “missing”

12. Problem Solving Strategies
Recognize the key physics principles
Need a conceptual understanding of the laws, how they are applied, and how they are interrelated
Sketch the problem
Show the given information / include a coordinate system
Identify the important relationships
Use the given information and the unknown quantities to determine what laws apply
Solve for the unknown quantities
What does it mean?
Does the answer make sense?
Think about your answer

13. Dealing With Numbers
Scientific notation
Significant figures

14. Scientific notation Number of people leaving on the Earth (2007):
Prefix (abbreviation)
Power
of Ten
Peta (P)
1015
Tera (T)
1012
Giga (G)
109
Mega (M)
106
Kilo (k)
103
Hecto (h)
102
Deci (d)
10-1
Centi (c)
10-2
Milli (m)
10-3
Micro ()
10-6
Nano (n)
10-9
Pico (p)
10-12
Femto (f)
10-15
Number of people leaving on the Earth (2007):
6,600,000,000
or 6.6 x 109

15. Significant figures – show accuracy
Your height is:
(A) 5.9 ft (B) 5.90 ft
B is more accurate than A, as its result contains more significant figures.
Implies that true value lies between 5.89 ft and 5.91 ft
A digit is significant if it is meaningful with regard to the accuracy of the value

16. Significant Figures in Calculations
Multiplying and dividing
Use the full accuracy of all known quantities when doing the computation
After completing the calculation, round the answer to the number of significant figures present in the least accurate starting quantity
Example: 976 x m = m~ m
Due to the 2 significant figures in the

17. Significant Figures - cont’d
What is the perimeter of a circle of radius 1.2 m?
L = 2r x … x 1.2 = … m
L = 7.5 m
What about:
= or = ?
Ans: 3.2 or 0.12
Lecture 1
Purdue University, Physics 220

18. Purdue University, Physics 220
Units
To communicate the result of a measurement for a quantity, a unit must be defined!
Defining units allows everyone to relate to the same fundamental amount.
Always write down units and carry the units through all of the calculations.
We use the SI system
Length: meter (m)
Mass: kilogram (kg)
Time: second (s)
Dimensional Analysis:
Both sides of an equation must have the same units.
Can be used to verify equations, answers.
Example: density [kg/m3]  = m [kg] / V [m3]
1 meter = ft
1 kg = pounds
Lecture 1
Purdue University, Physics 220

19. Trigonometry Generally will use only right triangles
Pythagorean Theorem
r2 = x2 + y2
Trig functions (r=hypotenuse)
sin θ = y / r
cos θ = x / r
tan θ = y / x
Trigonometric identities
sin² θ + cos² θ = 1
Other identities are given in appendix B and the back cover
To find an angle, you need to use the inverse of a trig function
If sin θ = y/r then
θ = sin-1 (y/r)= ascsin(y/r)
Angles in the triangle add up to 90°
α + β = 90°
Complementary angles
sin α = cos β

20. Vectors vs. Scalars
A scalar is a quantity that requires only a magnitude (with unit) – time [s], mass [kg].
A vector is a quantity that requires a magnitude and a direction (is represented by arrows) –displacement [m], force [N], velocity [m/s], acceleration [m/s2].

21. Vector Representation
The length of the arrow indicates the magnitude of the vector
The direction of the arrow indicates the direction of the vector with respect to a given coordinate system
Vectors are written with an arrow over a boldface letter
Mathematical operations can be performed with vectors: add, subtract, multiply by constant.

22. Adding Vectors Draw the first vector
Draw the second vector starting at the tip of the first vector
Continue to draw vectors “tip-to-tail”
The sum is drawn from the tail of the first vector to the tip of the last vector

23. Adding Vectors Using Components
Assume you are adding two vectors:
To add the vectors, add their components
Cx = Ax + Bx
Cy = Ay + By
Then the magnitude and direction of C can be determined
Ax = A cos θ; Ay = A sin θ

24. Purdue University, Physics 220
Motion -x +x
The variables are time and position
t = ti start of observations at a point xi
t = tf end of the observations at a point xf
The object is in motion and velocity is
(change in position)/time
Velocity can change => acceleration
(change in velocity)/time
All quantities except time are vectors; the vector “nature” is contained in whether the quantity is positive or negative
Lecture 1
Purdue University, Physics 220

25. Purdue University, Physics 220
Displacement
= change in position during a particular time interval
This type of x(t) plot shows the position of an object at any time, e.g.,
x (m) 3
Position at t=3 s, x(3) = 1 m
t (s) 4
Displacement between t=1 s and t=5 s
Dx = 1.0 m m = -1.0 m -3
Lecture 1
Purdue University, Physics 220

26. Purdue University, Physics 220
Question
Given the train’s initial position and its final position what is the displacement of the train?
Answer: B
A) -26 km
B) -29 km
C) +29 km
D) -23 km
E) +23 km
Lecture 1
Purdue University, Physics 220

27. Displacement vs Distance
Displacement is a vector
Only depends on the initial and final positions
Independent of actual paths between the initial and final positions
Distance is a scalar
Depends on the initial and final positions as well as the actual path between them
Lecture 1
Purdue University, Physics 220