c h a p t e r 1 introduction and mathematical concepts units: unit conversion, dimensional analysis...

C H A P T E R   1Introduction and

Mathematical Concepts

•Units: Unit conversion, Dimensional Analysis

•Trigonometry

•Vectors

1.1 The Nature of Physics

• What is physics?

1.1 The Nature of Physics

• Physics is the study of the fundamental laws of nature.

1.1 The Nature of Physics

• Physics is the study of the fundamental laws of nature.

• Physics deals with the behavior and structure of matter.

1.1 The Nature of Physics

• Physics is the study of the fundamental laws of nature.

• Physics deals with the behavior and structure of matter.

• Physics is very fundamental and the most basic of the sciences.

1.1 The Nature of Physics

• Physics is the study of the fundamental laws of nature.

• Physics deals with the behavior and structure of matter.

• Physics is very fundamental and the most basic of the sciences.

• The beauty of physics is its capacity for predicting how nature will behave in one situation on the basis of experimental data obtained in another situation.

Sub-Fields of Physics

Introductory physics is divided into the following

sub-fields:• Mechanics• Thermal physics• Wave motion and sound• Electricity and magnetism• Light and optics• Modern physics

Sub-Fields of Physics

Introductory physics is divided into the following

sub-fields:• Mechanics (Chapters 1-11)• Thermal physics (Chapters 12-15) • Wave motion and sound (Chapters 16-17)• Electricity and magnetism (Chapters 18-24)• Light and optics (Chapters 25-27)• Modern physics (Chapters 28-32)

Units    

System

SI CGS BE

SI stands for the French phrase "Le Systeme International d'Unitus."

CGS - centimeter (cm), gram (g), and second.

BE - British Engineering.

Units    

System

SI CGS BE

Length meter (m)centimeter (cm)

foot (ft)

SI stands for the French phrase "Le Systeme International d'Unitus."

CGS - centimeter (cm), gram (g), and second.

BE - British Engineering.

Units    

System

SI CGS BE

Length meter (m)centimeter (cm)

foot (ft)

Masskilogram (kg)

gram (g) slug (sl)

SI stands for the French phrase "Le Systeme International d'Unitus."

CGS - centimeter (cm), gram (g), and second.

BE - British Engineering.

Units    

System

SI CGS BE

Length meter (m)centimeter (cm)

foot (ft)

Masskilogram (kg)

gram (g) slug (sl)

Time second (s) second (s) second (s)

SI stands for the French phrase "Le Systeme International d'Unitus."

CGS - centimeter (cm), gram (g), and second.

BE - British Engineering.

Units of length

• Early units of length were associated with the human body.

Units of length

• Early units of length were associated with the human body.

• The foot was originally defined to be the length of the royal foot of King Louis XIV.

Units of length

• Early units of length were associated with the human body.

• The foot was originally defined to be the length of the royal foot of King Louis XIV.

• These units are not reproducible.

Earlier Definition of meter Metre (meter) originated from the Greek word metron meaning “measure”.

Earlier Definition of meter Metre (meter) originated from the Greek word metron meaning “measure”.

In 1793, the meter was defined in terms of the distance measured along the earth's surface between the north pole and the equator.

Standard Meter Bar

In 1799, a platinum-iridium meter bar, was used to define meter.

Standard Meter Today

Since 1983, meter is defined using the speed of light, 299 792 458 m/s.

The meter is the length of the path traveled by light in vacuum during a time interval of 1/299 792 458 of a second.

Standard Kilogram Today

The standard platinum-iridium kilogram is kept at the International Bureau of Weights and Measures in Sevres, France.

Units of time

• The Earth takes 24 hours to rotate once.

• Before 1956, the mean solar day was defined to be 24x60x60 = 86,400 seconds.

Standard Second Today

The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.

A cesium atomic clock.

 Physical Quantity

Unit

Name Symbol

Time second s

Length meter m

Mass kilogram kg

Electric current ampere A

Temperature kelvin K

Amount of substance

mole mol

Luminous intensity

candela cd

SI Base Units

Some SI Derived Units

• Area - m2

• Volume - m3

• Density - kg/m3

Conversion of Units

Dimensional Analysis

• In physics, the term dimension is used to refer to the physical nature of a quantity and the type of unit used to specify it.

Length- L, Mass-M, Time-T