equal to the sum of the squares of the other two sides minus twice the product of these two sides times the cosine of the angle between these two sides”.

**Physics:)**

Chapter 1

iNTRODUCTiON

Objectives:)

After studying this chapter, you should be able to:

Explain some methods and mathematical formulas needed in

physics

The Nature of Physics

The systematic development of the study of physics started with the studies made by Galileo, Kepler and Newton some three centuries ago when they tried to understand mechanical motions of objects. These efforts have been so successful that the laws of physics now encompass a remarkable variety of phenomena, including planetary orbits, radio and TV waves, magnetism, and lasers, to name just few.

Physics is a major science, dealing with the fundamental constituents of the universe, the forces they exert on one another and the results produced by these forces. It relates to the laws of symmetry and conservation, such as those pertaining to energy, momentum, and charges. Physics is concerned with the basic laws of nature. It deals with the study of matter and energy and their relationship.

Physics is all around us from the minute parts of the atom to the macroscopic universe. Physics is very useful. It is a science which we use everyday. It is a science we deal with in our daily life knowingly or unknowingly. We use physics in cooking food, ironing clothes, in writing letters or in looking at mirrors. There is physics in running automobiles, calesas and trains. There is physics in the flight of airplanes and jet planes. Physics is present in the construction of roads, bridges and buildings. Laws and principles of physics are used in practically every machine and in everything we do, Physics plays an important role in transportation, communication, amusement, sports, industry and the home.

Physics has raised our standard of living. The modern facilities in our home like refrigerators, air conditioning units, electric mixers, ovens, and microwaves, radios, television sets, and high fidelity radios, VCD’s and DVD’s made home life enjoyable.

Physics protects us from accidents by means of signal lights in the streets, lighthouses for ships, safe devices like fuses and lightning arresters in home and factories. Physics helps in prolonging life with useful instruments needed in hospitals and clinics and by providing rays that kill germs.

Physics makes us understand our environment, teaches us the

manipulation and operation of the many complicated and simple devices that are necessary in our modern life. In transportation, physics has given us the modern automobiles, locomotives, airplanes, jets, rockets, luxury liners, and atomic powered submarines. In communication, physics has given us telephone, cell phones, teletypes and telecast systems.

Knowledge of physics makes us appreciate the modern discoveries and inventions in science like the radar, the rocket, the atom ships, rain making, the radioisotopes and many others.

**1.2 Branches of Physics**

Physics is divided into two general branches—classical physics and

modern physics. Classical physics refers to the traditional topics in physics that were recognized and developed before the beginning of the 20th century. It involves the study of Newtonian mechanics,

thermodynamics, acoustics, optics, and electromagnetism. Modern

physics on the other hand refers to the concepts in physics that have surfaced since the beginning of the 20th century. It is concerned with the study of quantum mechanics, nuclear and particle physics, or plasma physics.

**1.2.1 Classical Physics**

Mechanics is the branch of physics which concerned with the study of forces acting on bodies, whether at rest or in motion.

a. Statics is concerned with the forces acting on bodies at rest.

b. Kinematics is concerned with bodies in motion without concerned

with what causes motion.

c. Dynamics is concerned with the bodies in motion and the forces that causes motion.

Thermodynamics is the physics subdivision which deals with heat

transfer and the conversion of heat to useful work through physical movement or chemical reactions.

Thermodynamics:)

Mechanics:)

Acoustic is the scientific study of sound waves and their

manipulations. In this field, physicist, employ their knowledge in a

wide range of endeavors, from studying the slow vibrations of earth to manipulating high-frequency, or ultrasonic, waves to diagnose, monitor, and even treat various medical conditions and disorders. Sound engineers apply the principles of acoustical physics to music production and theater design.

Acoustic:)

Optics refers to the study of all phenomena related to light.

Geometric optics deals with light as a straight line (which is called

a ray), and with effects such as reflection, refraction, and the

formation of images by optical instruments such as microscope, light filters, and cameras.

Optics:)

Electromagnetism is the branch of physics that studies the forces between magnetized objects, the forces between electric current, and how these two types of forces relate. Electromagnets in an industrial machine, such as generators, and motors, and those in scientific devices such as particle accelerators and superconductors.

Electromagnetism:)

**1.2.2 Modern Physics**

Quantum mechanics deals with the structure and behavior of atoms and subatomic particles from the point of view that all energy exists in the form of quanta. Quantum mechanics is the science of photoelectric cells and solar batteries, fluorescent lights, lasers, and spectroscopes (instruments used to identify elements by the light they emit when heated).

Quantum Mechanics:)

**Nuclear and particle physics concerns with the properties of the**

atomic nucleus and its particles, or nucleons. Nuclear physicists

develop nuclear energy and nuclear weapons by controlling and

harnessing the energy produced by nuclear-fission and nuclear-fusion reactions. They also work on the nuclear medicine, developing methods for using tiny amounts of radioactive “tracer” molecules to diagnose and treat diseases.

atomic nucleus and its particles, or nucleons. Nuclear physicists

develop nuclear energy and nuclear weapons by controlling and

harnessing the energy produced by nuclear-fission and nuclear-fusion reactions. They also work on the nuclear medicine, developing methods for using tiny amounts of radioactive “tracer” molecules to diagnose and treat diseases.

**Nuclear and Particle Physics:)**

Plasma physics deals with the properties and applications of plasma – a form of matter (sometimes considered as the fourth state of matter) that starts out as a gas and then becomes ionized into free-moving ions and electrons. Beyond earth’s atmosphere, more than 99 % of the observable matter in the universe appears to consist of plasma. In earth, plasma is found in few places such as in lightning, and in certain devices such as fluorescent tubes. Plasmas could be produced in the laboratory by ionizing gases with electric fields. This is used in semiconductor industry.

Plasma and Particle Physics:)

What is PHYSICS??

Define physics

Explain the importance of physics

Explain the different

divisions of physics

Express very large or very small

numbers using the scientific

notation forms

**1.2.3 Cross-Disciplines of Physics with other Sciences**

Biophysics studies the physics of living organisms. The use of tools and concepts of physics to solve biological problems such as the structure of complex molecules or the nature of electrical impulses in the brain, nerves, muscles, and other tissues. Example, X-ray diffraction played an important role in the discoveries of the structure and function of such important molecules as protein and DNA.

Biophysics:)

Geophysics applies physics to the study of Earth and neighboring

planets. It includes the study of Earth’s crust, core, oceans, and

atmosphere, and those of other planets in our solar system. Geophysics is divided into several subdivisions such as; geodesy, the study of the earth’s gravitational field and shape, seismology includes the study of seismic waves produced by earthquakes and other disturbances, such as underground nuclear explosions, geomagnetism deals with the nature of earth’s magnetic field and poles.

Geophysics:)

Physical chemistry deals with the structure of matter and the energy changes that occur during chemical reactions and changes in physical state (such as when gas changes to liquid).

Physical Chemistry:)

Cosmology studies the origin, structure, and evolution of the

universe. Physicists in this field also explore how mechanisms that

created the universe determine the fundamental nature of matter and energy. Cosmology is a branch of astronomy, but the observational and theoretical techniques used by cosmologists involve a wide range of other sciences, such as physics and chemistry. Cosmology is distinguished from cosmogony, which used to mean the study of the origin of the universe but now usually refers only to the study of the origin of the solar system.

Cosmology:)

Astrophysics, the branch of astronomy that seeks to understand the birth, evolution, and end states of celestial objects and systems in terms of the physical laws that govern them. It uses quantum mechanics as well as nuclear and particle physics to explain the appearance and behavior of stars and other celestial phenomena. Astrophysicists attempt to characterized everything observed in the larger universe in terms of temperatures, pressures, densities, and chemical composition.

Astrophysics:)

1.3.2 Scientific Notation

Physics involves quantities whose magnitudes range from very small to very large numbers. The compact way of writing down these numbers is made possible by the use of powers of ten notations, also called exponential notation. This is also called scientific notation because of its common use in scientific work.

In scientific notation, a number is expressed as a product of a coefficient multiplied by a power of 10. The coefficient is a number equal to or greater than 1 but less than 10. The power of ten is an exponent.

Scientific Notation:)

Formula: M x 10

n

exponent

Coefficient:)

where: m = is a number between 0 & 10

n = is a positive or negative integer

To write numbers in scientific notation the following steps must be followed:

1. Transfer the decimal point to the right or to the left so that the decimal point will just be immediately after the first nonzero digit.

2. The number of places the decimal has been moved is equal to the exponent. The exponent is positive if the decimal point is moved to the left of its original position, and it is negative if it is moved to the right.

Exponential Positional

2.35 x 105 235000

1.25 x 10 -6 0.00000125

1.0 x 10 6 1 000 000

1.0 x 10 -6 0.000 001

Example:

In mathematics the multiples and sub multiples of ten are written as follows:

100,000 = 10 x 10 x 10 x 10 x 10 = 105

10,000 = 10 x 10 x 10 x 10 = 104

1,000 = 10 x 10 x 10 = 103

100 = 10 x 10 = 102

10 = 10 = 101

1 = by definition = 100

0.1= 1 /10 = 10-1

0.01= 1/100 = 10-2

0.001= 1/1,000 = 10-3

0.0001= 1/10,000 = 10-4

0.00001= 1/100,000 = 10-5

It is clear that for every large numbers which are multiples of ten, the power or exponent is large and positive. For a very small numbers the power is negative.

Problems in physics involving mechanics are usually solved by the elementary principles of trigonometry, algebra and geometry. The concepts of trigonometric functions are one way of expressing the principles of proportionality.

A right triangle has one 900 angle. The perpendicular sides of the triangle are called the legs and the third side which is the opposite of the 900 angle is the hypotenuse. The sum of the two acute angles ( +) is 900. Angles and are complementary angles.

Consider angle , side a is the opposite, side b is the adjacent side, and side c is the hypotenuse.

1.4 Trigonometric Concepts

opposite side a

Sine = -------------------- = -----

hypotenuse c

adjacent side b

Cosine = -------------------- = ----

hypotenuse c

opposite side a

tangent = ------------------- = ----

adjacent side b

hypotenuse c

cosecant = ---------------- = ----

opposite side a

hypotenuse c

Secant = ----------------- = ----

adjacent side b

adjacent side b

Cotangent = ------------------ = ----

opposite side a

The Six Trigonometric Functions of a right triangle

The first three functions (sine, cosine, tangent) are used usually in solving problems involving vectors.

The Cosine Law and the Sine Law

SiNE LAW and COSiNE LAW are often used in the solution of

problems involving forces.

R = F + F – 2 F F Cos y

1

2

1

2

2

2

2

Where:

, beta, angle opposite to F2

, gamma, angle opposite to R

, alpha, angle opposite to F1

F1,F2, R, are the sides of an oblique triangle.

Sine Law:)

Sine Law states that “ In any triangle the side is

proportional to the sine of the opposite angle”.

F1 F2 R

----- = ------ = -------

Sin Sin Sin

fORMULA :0

prepared by:

Exceptionalka:)

K. A. Anthony T. Parreñas

Polaris 1-B

Group Members:

Michael B. Barredo

Aldrin Herradura

John Paul Calopez

Rules in Rounding Off Numbers:

I. When the first digit of those to be dropped is less than 5,

leave the preceding digit unchanged.

Ex. The number

56.748

rounded off to the nearest

0.1

becomes

56.7.

II. If the first digit of those to be dropped is greater than 5,

raise the preceding digit by 1.

Ex. The number

2.146

rounded off to the nearest

0.01

becomes

2.15

.III. If the first digit of those to be dropped is 5 and:

If any nonzero digits follow the 5, raise the preceding digit by 1. Ex. The number

21.4501

rounded off to the nearest

0.1

becomes

21.5

**chapter Quiz:)**

1. With your own understanding, how do you best describe PHYSiCS?? (5 pts.)

2. _____________ refers to the traditional topics in physics that were recognized and developed before the beginning of the 20th century.

a. Classical Physics c. Traditional Physics

b. Modern Physics d. 20th Century Physics

3. ______________ studies the origin, structure, and evolution of the universe.

a. Geophysics c. Structural physics

b. Astrophysics d. Cosmology

this will assess how much you have learned after the discussion on this topic

CHOiCES WiLL NEVER BE PROVIDED!

it would only be your choice!

GOD BLESS for the Exam

4. Express in Scientific Notation:

123425613560000000

12156153600000000000000

1200000212001332040

5. Write the formula of CoSine law.

6. Differentiate Classical Physics

from Modern Physics. (5 pts.)

7. Give 5 Cross Disciplines of Physics.

8. Which does not belong to the group?

a. Astrophysics c. Biophysics

b. Physical Chemistry d. Classical physics

**9. True or False:**

Geophysics applies physics to the study of Earth and neighboring

planets.

Geophysics applies physics to the study of Earth and neighboring

planets.

**10. True or False**

Acoustics, Statics, and Dynamics

are the 3 classification of MECHANiCS.

Acoustics, Statics, and Dynamics

are the 3 classification of MECHANiCS.

Different TYPEs of exam were included

and your SEATMATE's choice!