welcome to physics 220

Lecture 1 Purdue University, Physics 220 1

– Kinematics– Forces– Energy and Momentum– Rotations– Fluids– Harmonic Motion/Oscillations– Waves– Sound– Thermodynamics

Welcome to PHYSICS 220Prof. Norbert Neumeister


Course Format• Lectures Section 3:

– Time: Monday, Wednesday 12:30 - 13:20– Lecture Room: PHYS 114– Instructor: Prof. N. Neumeister– Office hours: by appointment– Office: PHYS 374 Phone: 49-45198 Email: [email protected] (please use subject: PHYS 220)

• Recitations: – Time: Friday 7:30 - 16:20– Teaching Assistants: D. Pandey, M. Overby, G. Prakash,

Prof. E. Fischbach– CHIP coordinator: Dr. V.K. Saxena, PHYS 176

• Laboratory:– Coordinator: Dr. A. Lewicki, PHYS 142– Location: PHYS 121


TextbookThe textbook is College Physics: Reasoning and Relationships, Vol I, by N.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!


Course Web Site

• Course Syllabus– Policies– Grading scheme– Exams & iClicker exercises

• Lab Syllabus• Tentative Class Calendar (Schedule)

– Pre-lecture reading assignments– Homework due dates

• CHIP User’s Guide– Homework– Grades

http://www.physics.purdue.edu/phys220


Lectures• Participation is key

– Come to the lectures prepared!

• Not everything you need for exams– Concepts, Connections, Motivation– Comprehensive Text– Problem Solving: Homework + Recitation– Hands-On Lab

• I will not be able to cover all the material in the lectures, so part you will need to read from the textbook.

• Taking Notes– Lecture notes can be downloaded from the course web site– Some key pieces for you to fill in


iClicker• We will use iClicker for interactive lecture quizzes

– Two questions per lecture– One point for attendance– One point for each correct answer

• iClicker an 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!• See “Quick Guide to CHIP”

– Deadline: by the end of this week• We will start during the second week of class• Will count toward your final grade!


Recitation• Developing problem-solving skills• Must complete your homework before the

recitation• For due dates see course web site (Calendar)


Homework• We will use CHIP (Computerized Homework In

Physics) for homework assignments• The homework is due by 7 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.


General InformationRoom PHYS 144: Undergraduate officeRoom PHYS 11: Help centerRoom PHYS 290: Physics Library

For questions concerning CHIP contact:Dr. V.K. Saxena: Office: PHYS 176, Phone: 49575Click on "Problem Report" link on course's CHIP web page, or send email to [email protected] . You need to identify yourself by giving your full name and Purdue Student ID number.

You will be able to access your grade-book (using CHIP) and check the latest scores. It is your responsibility to check your score on a regular basis.You will find more information about accessing and using CHIP on a separate handout available from room 144.http://chip.physics.purdue.edu/public/220/fall2009/


Activities and Responsibilities• In-class activities and responsibilities

– Coming to lectures, taking notes, asking questions– Participate in the lecture quizzes– You are responsible for attending all classes– If you miss class, it is your responsibility to find out what you missed

• Outside class– Read and keep up to date with the text

• Read the assigned textbook sections thoughtfully• Stop and ask yourself if you understand what you just read

– Going to recitation, doing homework on CHIP– Doing extra problems, old exams

• Work as many problems as you can - more than just the assigned homework problems

– Getting help when you need it

• Homework– All web based; homework assignments will be posted through CHIP


Exams and Grades• Exams:

– There will be two evening exams and a final exam. All exams are closed-book, but relevant formulas and constants will be provided where needed. The final exam will be cumulative.

– Exam 1: Oct 1, 2009, 20:00 - 22:00– Exam 2: Nov 17, 2009, 20:00 - 22:00– 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 recitation (homework)• 150 points laboratory• 100 points lecture quizzes• 1000 points total

– We will use plus/minus letter grades.– The exact cut-offs for letter grades will not be determined until the

end of the semester.– You must the lab in order to pass the course.


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 SI system

– Length: meters– Mass: kilograms– Time: seconds

• Dimensional Analysis:– Both sides of an equation must have the same dimensions– Can be used to verify equations, answers

1 meter = 3.281 ft1 pound = 4.448 N1 kg weighs 2.205 pounds (where g = 32.174ft/s2 )

Scientific Notation• Scientific notation is a useful way to write numbers that are very large or

very small• To write a number in scientific notation:

– Move the decimal point to create a new number between 1 and 10• Not including 10

– Count the number of places the decimal point was moved• This is the exponent of 10• The exponent is positive if the original number is greater than one• The exponent is negative if the original number is less than one

• There is an uncertainty associated with all measurements– Uncertainty is also called experimental error

• Values are written using significant figures– A digit is significant if it is meaningful with regard to the accuracy of the value

• Zeros may be ambiguous– Scientific notation helps clarify the significance of any zeros



Significant FiguresYour height is:

A) 5.9 ft B) 5.90 ft

B is more accurate than A, as its result contains more significant figures.

The financial bailout:

$700,000,000,000

What about $7.0010 x 1011?

or $7 x 1011

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 (µ) 10-6

Nano (n) 10-9

Pico (p) 10-12

Femto (f) 10-15


Significant Figures - cont’d

What is the perimeter of a circle of radius 1.2 m?

What about:

3.1415 + 0.1 = 3.2415 or 0.1415 - 0.02 = 0.1215?

Answer: 3.2 or 0.12

L = 2πr = 2 x 3.1415926 … x 1.2 = 7.539822 … m

L = 7.5 m

Trigonometry• Generally will use only right triangles• Pythagorean Theorem

– r2 = x2 + y2

• Trig functions– sin θ = y / r– cos θ = x / r– tan θ = y / x

• Trigonometric identities– sin² θ + cos² θ = 1

• 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)

• Angles in the triangle add up to 90°– α + β = 90°

• Complementary angles– sin α = cos β



Vector


Vector and Coordinate System

Motion• Defined in terms of various concepts• Look at motion in terms of

– Velocity and speed– Velocity and position– Average velocity and instantaneous velocity– Acceleration– Velocity and acceleration

• Concepts needed– Position– Velocity– Acceleration

• Start by considering one-dimensional motion• Can be shown by a motion diagram

– Could be a multiple exposure – Sometimes is a sketch



+x-x 0

The variables are time and positiont = ti start of observations at a point xit = tf end of the observations at a point xf

All quantities except time are vectors; the vector “nature” is contained in whether the quantity is positive or negative

Motion

The object is in motion and velocity is (change in position)/timeVelocity can change => acceleration (change in velocity)/time


Displacement= change in position

x (m)

t (s)4

3

-3

Displacement between t=1 s and t=5 s

Δx = 1.0 m - 2.0 m = -1.0 m

This type of x(t) plot shows the position of an object at any time, e.g.,

Position at t=3 s, x(3) = 1 m


Given the train’s initial position and its final position what is the displacement of the train?

A) -26 kmB) -29 kmC) +29 km

D) -23 kmE) +23 km

Question


Displacement vs Distance• An object’s change in position is its displacement

– Displacement: Δx = xfinal - xinitial

• 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


Summary of Concepts• Kinematics: A description of motion• Position: your coordinates• Displacement: Δx = change of position

welcome to physics 220

Documents