Welcome to Physics-131Physics-I

TARIQ H. GILANI

ASSOCIATE PROFESSOR MILLERSVILLE UNIV. ASSISTANT PROF (2002).

PENN STATE UNIVERSITYSTATE COLLEGE, PA (2000) ----- POST DOC.

JOHN CARROLL UNIVERSITYCLEVELAND, OH (2001) ----- VISITING ASS. PROF.

PhD ---- KYOTO UNIVERSITY, JAPAN (1997).

Office: R 236 (STB) Ph. 871-7449

E-mail: tariq.gilani@millersville.edu

Welcome to

Physics 131

Text: Physics, 9th Edition, Cutnell and Johnson

Lab Notebook: Bound Lab Notebook, quad ruled, (9.75” x 7.5”).

Please bring this lab notebook to your first meeting.

A scientific calculator for use in Lab.

Reference Books:

1. Physics, 2nd Edition, Urone.

2. Physics For Scientists and Engineers, 4th Edition, Serway.

3. University Physics, 10th Edition, Young & Freedman.

PurposeIt is an introductory algebra-based course. To become familiar with basic ideas of physics – Mechanics, Heat, Energy, Waves and Sound. The primary focus will be on concepts

Class

Lectures Discussion Problems Demonstrations

Each Lab must be satisfactorily completed to pass this course

There will be Four in-class exams during the semester (Each

Friday). In addition to the exams, laboratory and attendance

will be considered. Each of these counts towards your final

grade as follows: Tentative Dates

In-class exams 80% Every Friday

Attendance 10% --------Labs: 10% -------------------

Exams and Grading

Each Lab must be satisfactorily completed to pass this course

Labs

You must complete all lab work.

Missed WorkIf you miss a lab or exam for any reason, you must contact your instructor as soon as possible for arrangement.

My phone # 871-7449, e-mail: tariq.gilani@millersville.edu

Department office: 872-3411 (In case you have difficulty in finding me)

90-100% A 65-69.9% C+

85-89.9% A- 60-64.9% C

80-84.9% B+ 55-59.9% C-

75-79.9% B 50-54.9% D+

70-74.9% B- 45-49.9% D

<45% F

The minimum score for any grade may be lowered based on the difficulty of quiz or

examination questions.

Syllabus and Other Information

www.millersville.edu/~tgilani

What is Phys 131?

Physics

MechanicsHeat and Energy

Waves and Sound

What is Physics?

• Observing and understanding the Physical world ----- Physics is most basic of all sciences.

• It predicts “how nature will behave in particular situation on the basis of experiments.

Physics --- Study of basic nature of matter and the interactions that govern the behavior

• Space Science• Transportation Industry• Electronics and Computer Science•Medical Equipments

In Physics

Physics tells us the rules of the universe.

To enjoy more!!

• How to see the world?

• Use reasoning

• Apply the Physical Principles

Measurements

First step --- defining units

Measurements must be accurate, precise and reproducible

Research needs communication among international researchers

Common Language --- System of Units

Experiments involve the measurements of quantities

How small an atom is? System of measurements

SI CGS BE SI is most widely used

Length, Mass and TimeAlong with few more are base

Their units are basic units

All other units are derived

Metric UnitsLength -------- meters (mm, cm, km,…)

Mass --------- Kilograms (mg, cg, g, …)

Time ---------- seconds (ns, ms, …)

Main Advantage

Conversion within the system is quite easy

MKS CGS BE

Length

Mass

Time

Meter (m) centimeter (cm) foot (ft)

Kilogram (Kg) gram (g) Slug (Sl)

Second (s) Second (s) Second (s)

1 Kg = 1000 g

1 g = 1000 mg

• English System

• Metric system1999--- NASA’s Mars climate orbiter became a victim of confusion.

Cost US$125 million

SI System (International system):

Three basic units of measurements

Length or distance

Mass

Time

Meter (m)

Kilogram (kg)

Second (s)

SI System or MKS system

Kilometer (km) centimeter (cm)

Mega meter (Mm) millimeter (mm)

Giga meter (Gm) micrometer (m)

nanometer (nm)

Power of 10

Example:

100,000 = 105 and 0.00001 = 10-5

1000 = 103 1Million = 106

1 Micro = 10-6 and so on

To multiply

102X106 =

105X10-7 =

To divide

102/106 =

105/10-7 =

The universe is only seconds old

A Million Trillion seconds

106X1012 = 1018s

Prefix Figure Scientific Words Notation

giga = 1000,000,000 = 109 = 1 billionmega = 1000,000 = 106 = 1 millionkilo = 1000 = 103 = 1 thousandcenti = 1/100 = 0.01 = 10-2 = 1 hundredthmilli = 1/1000 = 0.001 = 10-3 = 1 thousandthmicro = 1/1000,000 = 10-6 = 1 millionth nano = 1/1000,000,000 = 10-9 = 1 billionth

Commonly used Metric Prefixes

Can you tell with out using calculator?

• How many inches are there in 6 miles?

• How many meters are there in 6 km?

How small an atom is? Pretty small

1 Million (106) atoms if put together can not be bigger than this period at the end of this sentence.

•1970 --- First direct evidence of atom using SEM

•1983 --- First 3-D image of an atom was obtained using STM

Atoms were dragged and arranged to write the name of laboratory (IBM).

Whatever system of units you use --- be consistent

Can not mix ---- length in ft and mass in kg

A quantity is always expressed by a number and its units (if it has)

Distance --- units of length

Speed in units of length divided by units of time Dimensions

Dimension of speed =Dimension of Length

Dimension of Time L

TS =

Dimension AnalysisFirst check of mathematical relation

Mathematical relation must have same dimensions on both side of the equation

Example

X = ½ v t2

L H S R H S

X is distance

v is speed

t is time

L

Dimensions

LT

T2

= L T

Relation is wrong

X = ½ v t has the right dimensions

Trigonometry

Basic RelationsHypoten

use h

Adjacent ha

opposite ho

h

hoSin

h

hCos a

a

o

h

hTan

h2 = ho2 + ha

2

Scalars and Vectors

Scalar --- Quantity that need magnitude only

Vector --- Quantity that need magnitude and direction

Mass, Volume, Temperature

Force, displacement

Arrow --- direction

Length --- magnitude

2 Km due East

4 Km due East

Vector is represented by Boldface letter or Arrow on the symbol

A or A

A scalar is represented by italic symbol A

A vector has magnitude and direction

A = 2 m due west Magnitude = 2 m

Vector Addition

Magnitude and direction

• When all vectors are in the same directionA = 2 m due East and B = 5 m due East

Their resultant R = A + B = 7 m due East

• When two vectors are pointing opposite

A = 2 m East B = 5 m West

=> R = 3 m West

• Perpendicular vectors

A = 2 m East B = 5 m North

EastWest

North

South

A

BR

R = [A2 + B2]1/2

Direction )(1

A

BTan

Degrees North of East

• Draw Vector A

• Draw vector B starting at the arrow of A

• R (= A + B) is from tail of A to head of B

• Measure the Length and angle of R

Graphical Method

Must use same scale

Subtraction

A – B = A + (- B)

Multiplying a vector with -1

magnitude remains the same while direction is reversed=>

A = 2m East -A = 2m west

Vector Components

x-component Along x-axis

y-component Along y-axis

X-axis

y-axis

A = 2 Km at 30 o North of East

A

Ax

Ay

Ax = A cos Along x-axis

Ay = A Sin Along y-axis

Adding by Vector components

A = 2 Km 30o North of East B = 3 Km 60o North of East

Ax = 2 Cos (30o) Bx = 3 Cos (60o)

Ay = 2 Sin (30o) By = 3 Sin (60o)

Rx = Ax + Bx Ry = Ay + By

R = [R2x + R2

y ]1/2

)(1

x

y

R

RTan

Summary

• Units ---- SI System (length m, Mass Kg and Time s).

• Dimensions --- First check of Mathematical relation.

• Trigonometry --- Cosine, Sine and Tangent functions.

• Scalar and Vector Quantities.

• Scalar can be described completely by magnitude

• Vector needs direction along with magnitude to be fully described.

• Vector Addition and Subtraction

• Graphical Method

• Vector Components Method

Practice

• Are two vectors with the same magnitude necessarily be

equal?

• Conceptual Questions (FOC): 8, 15, 17

• Problem 6, 15, 37, 40, 46 and 49