INTRODUCTION TO PHYSICS MASLINDA MAT SHARIF Faculty of Engineering, City Univ. College of Sc. & Technology Lecture Hours: Tuesday 08.00am-10.00am, City 2.09 (Lecture) : Tuesday 10.00am-11.00am, City 2.09 (Tutorial)

INTRODUCTION TO PHYSICS The word ‘Physics” has its origin from Greek word Physikos which means knowledge of the nature The goal of physics is to gain a better understanding of the world in which we live, to explain the fundamental nature of the universe by using simple explanation

Generally, the questions “why?’’ and “How? ” help us to find answers that are related to the mysteries of the universe. This majority of the natural phenomena can be explained by using the principle of physics

Fields of studies in physics Classical PhysicsModern Physics

Classical Physics Electricity Heat Light Magnetism Mechanics Sound

Modern Physics Atomic Molecular Electron physics Nuclear physics Particle physics Relativity Origin of universe Astrophysics

Important of physics Physics is important in science such as astronomy, biology, chemistry and geology Used in practical developments in engineering, medicine and other technology Research in physics led us to the studies of radioactive materials, diagnosis and treatment of certain diseases.

Contribution of physics to mankind YEARDISCOVERY AND CONTRIBUTION BASED ON PHYSICS Discovery of radioactivity 1897Discovery of the electron 1900Discovery of quantum energy 1901Electromagnetic waves across the Atlantic Ocean (Transatlantic telegraph cables) 1905The Theory of Relativity

Relation physics and Biology Until a few hundred years ago, phyics biology and chemistry were all the one subject. The split first happened in bio/physics between living and on living sciences and then chemistry branched off from physics as just the study of the electron. Read more: cs_have_to_do_with_biology#ixzz1EBiofR6t cs_have_to_do_with_biology#ixzz1EBiofR6t

APPLICATION PHYSICS IN BIOLOGY Biomedical Physics Group the application of ultrasonic techniques to physiological and medical problems. Magnetic Resonance Imaging of Lungs develop techniques for magnetic resonance imaging of human lungs Neurophysics

UNDERSTANDING BASE QUANTITIES AND DERIVED QUANTITIES Physical Quantities A physical quantity is a quantity that can be measured. A physical quantity can be divided into base quantity and derived quantity.

Base Quantities Base quantities are the quantities that are conventionally accepted as functionally independent of one another. It is a quantity that cannot be defined in term of other physical quantity. The base quantities and its units are as in the table below:

The SI unit is based on the French System of units or known as Le System International d’Unites in French. Base quantitySI units NamesymbolNamesymbol Lengthlmeterm MassmkilogramKg TimetsecondS Electric currentIampereA TemperatureTKelvinK

DERIVED QUANTITIES A derived quantity is a Physics quantity that is not a base quantity. It is the quantities which derived from the base quantities through multiplying and/or dividing them.

Example (Speed is derived from dividing distance by time.)

Derived Unit The derived unit is a combination of base units through multiplying and/or dividing them.

PREFIXES Prefixes are the preceding factor used to represent very small and very large physical quantities in SI units.

Conversion of prefixes Prefixes to Normal Number Example 1 The frequency of the radio wave is 350M Hz. What is the frequency of the radio wave in Hz? Answer Mega (M) = 1,000,000 or 10 6 Therefore, 350MHz = 250 x 10 6 Hz

Example 2 The thickness of a film is 25nm. What is the thickness in unit meter? Answer nano (n) = or Therefore 25nm = 25 x nm

Normal number to Prefixes Example s is equal to how many ms. Answer mili (m) = or To write a normal number with prefixes, we divide the number with the value of the prefixes s = ÷ = 25.5 ms

Example 4 Convert 265,500,000 W into GW. Answer Gega (G) = 1,000,000,000 or 10 9 Therefore 265,500,000 W = 265,500,000 ÷ 10 9 = GW

SCALAR AND VECTOR QUANTITY Scalar Quantity Scalars are quantities which are fully described by a magnitude alone. Magnitude is the numerical value of a quantity. Examples of scalar quantities are distance, speed, mass, volume, temperature, density and energy.

Vector Quantity Vectors are quantities which are fully described by both a magnitude and a direction. Examples of vector quantities are displacement, velocity, acceleration, force, momentum, and magnetic field.

Example 1 Categorize each quantity below as being either a vector or a scalar. Speed, velocity, acceleration, distance, displacement, energy, electrical charge, density, volume, length, momentum, time, temperature, force, mass, power, work, impulse.

Answer: Scalar Quantities: speed distance energy electrical charge density volume length time temperature mass power work

Vector Quantities velocity acceleration displacement momentum force impulse