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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.
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