Ahmad FauziUNS Physics Education DepartmentPhone 0856 4725 6315Email: fauziuns@gmail.com or fauzi_uns@yahoo.comBlog: fauziuns03.wordpress.com or fauziuns79.wordpress.com

Materials Chap.1 Physics and Measurement Chap. 2 Motion in One Dimension Chap. 3 Vectors Chap. 4 Motion in Two Dimensions Chap.5 The Laws of Motion Chap.6 Circular Motion and Other Applications of

Newton's Laws Chap.7 Fluid Mechanics Chap.8 Oscillatory Motion

Course Information: Instructor Instructor: Ahmad Fauzi, M.Pd. Office: the 2nd floor of D buildingTelephone: 0856 47256 315 Email: fauziuns@gmail.com or fauzi_

uns@yahoo.comBlog: fauziuns03.wordpress.com or

fauziuns79.wordpress.com

Materials Textbook

Raymond A. Serway and John W. Jewett.2004. Physics for Scientists and Engineers.USA: Thomson Brooks/Cole.

Resnick,R and Halliday, D.1997. Fundamental Physics. John Wiley & Sons, Inc.

Tipler. Physics for Scientists and Engineers.Hewitt. 1993. Conceptual Physics.New York:

Harper Collins College Publisher.

What is “Physics” and Why study “Physics” ???

Physics is concerned with the description and understanding of nature (physical world) in an objective way.

Measurement is one of its important tools.

nature (physical world)Physical world here refer to phenomena or

events, and can be classified into few categories:

MechanicsHeatElectricityMagnetismWaves and OpticQuantumand ….. Etc.

MechanicsPhysics

Kinematics and Dynamics

Electricity and MagnetismPhysics

Electricity and Magnetism

Light and OpticsPhysics

Light

ThermodynamicsPhysics

Thermodynamics

Physics

Objective way, Physical quantities

Description

• Model,

• Theories

• Laws,

• Equations

Nature (physical world)

Mechanics Heat

Waves and Optic Quantum … and etc.

Measurements Quantities

Measurements Quantities

Units Instruments

Vector QuantitiesScalar Quantities

Accuracy & UncertaintyDimension

Analysis Significant Figures

Accuracy and Precision:

The only kind of physical quantity that can be measured with complete accuracy would occur in simple counting operations, such as I have 25 Bahts and 13 Sattangs, or I see two dogs.

In physics, as in other sciences, quantities such as length, mass, volume and density of objects often have many different values.

ACCURACY and PRECISION are terms that are often used in regard to a measured quantity.

Accuracy and Precision:

ACCURACY is concerned with how close a measurement comes to the accepted or true value.

PRECISION is the agreement between the numerical values of two or more measurements that have been made in the same way

Precise measurements are not always necessary to be accurate.

Physics and Measurement \Physics deals with the nature and properties of matter

and energy. Common language is mathematics. Physics is based on experimental observations and quantitative measurements.

Mechanics deals with the motion and equilibrium of material bodies and the action of forces.

Classical Mechanics: Theory that predicts qualitatively & quantitatively the results of experiments for objects that are NOT Too small: atoms and subatomic particles – Quantum

Mechanics Too fast: objects close to the speed of light – Special Relativity Too dense: black holes, the early Universe – General

RelativityClassical mechanics deals with a lot of our daily life

objects!

MeasurementBeing quantitative in Physics requires

measurements.How tall is Ming Yao? How about his weight?

Height: 2.29 m (7 ft 6 in)Weight: 141 kg (310 lb)

Number + Unit

“thickness is 10.” has no physical meaning.Both numbers and units are necessary for any meaningful physical measurement.

Type QuantitiesMany things can be measured: distance,

speed, energy, time, force ……These are related to one another: speed

= distance/ timeChoose three basic quantities:

LENGTHMASSTIME

Define other units in terms of these.

SI Unit for 3 Basic QuantitiesMany possible choices for units of

Length, Mass, Time (e.g. Yao is 2.29 m or 7 ft 6 in)

In 1960, standards bodies control and define Système Internationale (SI) unit as,LENGTH: MeterMASS: KilogramTIME: Second

SI Length Unit: MeterFrench Revolution

Definition, 17921 Meter = XY/10,000,0001 Meter = about 3.28 ft1 km = 1000 m, 1 cm =

1/100 m, 1 mm = 1/1000 mCurrent Definition of 1

Meter: the distance traveled by light in vacuum during a time of 1/299,792,458 second.

SI Time Unit: Second 1 Second is defined as “atomic clock”– time taken

9,192,631,700 oscillations of the light emitted by a 133Cs atom.

Defining unit precisely is a science (important for, for example, GPS):◦ This clock will neither gain nor lose a second in 20 million

years.

SI Mass Unit: Kilogram1 Kilogram – the mass of a

specific platinum-iridium alloy kept at International Bureau of Weights and Measures near Paris.

Copies are kept in all other countries.

Yao Ming is 141 kg, equivalent to weight of 141 pieces of the alloy cylinder.

January 20, 2009

Length, Mass, Time

10x Prefix

Symbol

x=18

exa E

15 peta P12 tera T9 giga G6

megaM

3 kilo k

2

hectoh

1 deca da

3,000 m = 3 1,000 m = 3 103 m = 3 km 1,000,000,000 = 109 =

1G 1,000,000 = 106 = 1M 1,000 = 103 = 1k

141 kg = ? g 1 GB = ? Byte = ? MB

10x Prefix

Symbol

x=-1

deci d

-2 centi c-3 milli m-6

microµ

-9 nano n-12 pico p

-15

femtof

-18 atto a

0.003 s = 3 0.001 s = 3 10-3 s = 3 ms 0.01 = 10-2 = centi 0.001 = 10-3 = milli 0.000 001 = 10-6 = micro 0.000 000 001 = 10-9 =

nano 0.000 000 000 001 = 10-12 = pico = p

3 cm = ? m = ? mm

Derived Quantities and Units Multiply and divide units just like numbers Derived quantities: area, speed, volume, density ……

◦ Area = Length Length SI unit for area = m2

◦ Volume = Length Length Length SI unit for volume = m3

◦ Speed = Length / time SI unit for speed = m/s

◦ Density = Mass / Volume SI unit for density = kg/m3

In 2008 Olympic Game, Usain Bolt sets world record at 9.69 s in Men’s 100 m Final. What is his average speed ?

m/s 10.32s

m

9.69

100

s 9.69

m 100speed

Other Unit System U.S. customary system: foot, slug, second Cgs system: cm, gram, second We will use SI units in this course, but it is useful

to know conversions between systems.◦ 1 mile = 1609 m = 1.609 km 1 ft = 0.3048 m = 30.48

cm◦ 1 m = 39.37 in. = 3.281 ft 1 in. = 0.0254 m = 2.54

cm◦ 1 lb = 0.465 kg 1 oz = 28.35 g 1 slug = 14.59

kg◦ 1 day = 24 hours = 24 * 60 minutes = 24 * 60 * 60 seconds

Unit Conversion Example: Is he speeding ?

◦ On the garden state parkway of New Jersey, a car is traveling at a speed of 38.0 m/s. Is the driver exceeding the speed limit?

◦ Put 1’s using unit conversion relations, as many times as necessary.

◦ Multiply or divide numbers and units.◦ Begin with 38.0 m/s = (38.0 m/s) 1 ◦ Since 1 mile = 1609 m, so we have 1 = 1 mile/1609 m◦ Then (38.0 m/s) (1 mile/1609 m) = 2.36 10-2 mile/s◦ 2.36 10-2 mile/s = (2.36 10-2 mile/s) 1 1 1 = (2.36 10-2 mile/s) (60 s/1 min) (60 min/1h) = 85.0

mile/h