Chapter 1

Module 1
 Physics: A
Basic Science

1.1 PHYSICS AND OTHER BRACHES OF
SCIENCE

It is a systematized body of
knowledge that is based on facts
gathered through observations,
experiences and experiments in
order to formulate a verifiable
conclusion or law that serves as
basis of technology for the benefit
of man and his environment.

It is the
application of
the theoretical
sciences.

It deals
with the human
behavior primarily in its
social and cultural
needs.

It deals with the
human behavior
primarily in its
social and cultural
needs.

It deals
with the human
behavior primarily
in its social and
cultural needs.

It
deals with the
understanding and
description of nature,

It deals with the
understanding and
description of nature

Biological
Science

It deals with the study
of living things.

Physical
Science

It deals with the study of
non living things.

1.2 PHYSICS AND ITS BRANCHES

WHAT IS Physics?

This is the study of matter and
energy and their relationship.
Physicists believe that most everyday
phenomena can, in one way or
another, be explained through physics,
as matter and energy are the basic
constituents of the natural world. We
may not be aware of it, but everything
we see and don’t see is simply matter
and the energy it possesses.

This is also divided into two main 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.
MODERN PHYSICS – refers to concepts in
physics that have surfaced since the
beginning of the 20th century. This is mostly
concerned with the behavior of matter and
energy under extreme conditions(the very
large or the very small)

SUBBRANCHES OF PHYSICS
• Classical Physics
•Mechanics – the study of forces acting on bodies whether at
rest or in motion.
•Statics – on forces acting on bodies at rest.
•Kinematics – on motion without regard to its cause.
•Dynamics – on motion and the forces that affect it
•Acoustics – the study of the production and propagation of
sound waves.
• Optics – the study of light.
•Physical optics – on the production, nature and
properties of light.
•Physiological optics – on the part played by light in
vision.
•Geometrical optics – on the reflection and refraction of
light as encountered in the study of mirrors and lenses.
•Thermodynamics – the study of the relationship between
heat and other forms of energy.
•Electromagnetism – the study of the properties of electric
current and magnetism, and their relationship.
- Electrostatic - Electrodynamics
- Magnetostatics

•Modern Physics
•Atomic and Nuclear Physics – the study of the
components, structure, and behavior of the nucleus in
the atom.
•Quantum Physics – the study of the discrete nature of
phenomena at the atomic and subatomic levels.
•Relativistic Physics – the study of phenomena that take
place in a frame of reference that is in motion with respect
to an observer.
•Solid State Physics – the study of all properties of solid
materials.
•Condensed Matter Physics – the study of the properties of
condensed materials with the ultimate goal of developing
new materials with better properties.
•Plasma Physics – the study of the fourth state of matter.
•Low – Temperature Physics - the study of the production
and maintenance of temperature down to almost absolute
zero, and various phenomena that occurs only at such
temperature.

1.3 PHYSICS IS MORE THAN JUST A NATURAL
PHILOSOPHY
Physics was separated from philosophy because of one
important factor – it employed an approach known as
scientific method.
Scientific Method – is the application of a logical process
reasoning to arrive at a certain law or principle that is
consistent with experimental results.

1.4 PHYSICS AND TECHNOLOGY : PARTNERS FOR
PROGRESS
Physics, which attempts to understand nature and its laws, has
become a very important field of human knowledge. It has
helped us change both the physical and social dimension s of
our environment through the development of technology in the
form of new tools, or gadgets, new products and new
processes.

PHYSICS IS MORE THAN JUST A NATURAL
PHILOSOPHY
Physics was separated from philosophy because of

scientific method. Module 2
one important factor – it employed an approach known as

Scientific Method – is the application of a logical process of
 Nature’s Laws are
reasoning to arrive at a certain law or principle that is
consistent with experimental results.
Mathematical and
PHYSICS AND TECHNOLOGY: PARTNERS FOR
PROGRESS
Simple
Physics, which attempts to understand nature and
its laws, has become a very important field of human
knowledge. It has helped us change both physical and
social dimensions of our environment through development
of technology in the form of gadgets, new products and new
processes.

2.1 MATHEMATICS: AN ESSENTIAL TOOL
Physics without mathematics is unthinkable. We will
find out that the basic rules governing the behavior of nature are
readily expressed in mathematical form throughout the study of
physics.

2.1.1 Scientific Notation

Physics involves concepts which are described by very large or
very small quantities. Consider the following:

Mass of the earth :
6 000 000 000 000 000 000 000 000 kg

Mass of an electron:
0.000 000 000 000 000 000 000 000 000 000 911 kg

These very huge and minute magnitudes will take up much space
when written down and are difficult to use in calculations. To work
with these quantities more easily, you can express them in a
compact way of writing over a wide range of values known as
scientific notation.

In scientific notation, the numbers are represented by the product
of a multiplying factor and a power of ten.

In adding or subtracting numbers expressed in scientific notation,
quantities must have the same exponents as well as units. If the
powers of ten are not the same, they must be made the same.

In multiplying numbers using scientific notation, the product of
these must be the product of the base numbers and 10 raised to
the sum of their exponents.

In dividing numbers written in scientific notation, the quotient of
these id the quotient of the base numbers and 10 raised to the
difference of their exponents.

2.1.2 Significant Figures
In studying physics, we will do a lot of measurements of physical
quantities. When we record and report the numerical values of
measurements, we must express them in a numerical form which is
composed of digits that are known with certainty plus the first uncertain
digit. These digits are known as significant digits or significant
figures.
In general, the number of significant figures of a numerical quantity is
the number of reliably known digits it contains and is based on the
precision of the instrument used in measuring the quantity.
Rules in determining significant figures
1.Leading zeros are not significant, they simply locate the
decimal point.
Ex. 0.000143 has three significant figures.
2. Zeros between two nonzero digits are significant.
Ex. 105.03 has five significant figures.
3. Trailing zeros are usually significant, but can be ambiguous.
Ex. 100. has three significant figures.
1.00 has three significant figures.
100 is ambiguous.

In multiplication or division of numbers using significant figures , the
general rule is that the results are as precise as the least precise value,
that is, the value with the fewest significant figures.

In addition or subtraction, the precision of the result is no better than that
of the least precise quantity being calculated. It means that the result
occupies the same position relative to the decimal point as the position in
the number whose last significant figure is the farthest to the left.

2.2 MEASUREMENT: A UNIVERSAL LANGUAGE

Measurement are used to describe such quantities as
length, weight, area, volume, and time. It is a
quantitative description of a fundamental property or
physical phenomenon. When we measure, we compare
an unknown quantity with a certain standard called unit
of measurement.

2.2.1 Standard Units of Measure

This table shows the different quantities with their corresponding
units.

A. FUNDAMENTAL QUANTITIES

B. DERIVED QUANTITIES

→
v
→
a

2.2.2 Conversion of Units

Units in different system or even different units in the same
system can express the same quantity. To avoid confusion, it
is therefore necessary to convert the units of a quantity from
one unit to another.

Conversion of units can be done by multiplying the original unit
by an appropriate conversion factor. Conversion factors are
simply equivalence statements expressed in the form of ratios
equal to 1.

In converting units, we must take advantage of unit analysis.
That is, choosing the appropriate form of conversion factor that
will allow cancellation of unwanted units and thus give the
answer in the desired unit.

2.2.3 Minute and Huge Measurement
A better method of measuring small distances is by the use
of the micrometer and the vernier caliper.
Micrometer are used to make accurate measurements of the
thickness of a sheet of paper and the external diameter of
thin wires.
Vernier caliper is used for measuring wither the internal or
external diameters of tubes, pipes , rods, etc. The distance
between the jaws of the caliper is read on a scale attached
to the instrument.

2.2.4 Not All is Certain: The Limits of
Measurement

There is no such thing as a perfect measurement. Every
measurement, whether made by a student or a
professional scientist, contains a certain degree of
uncertainty.

Uncertainty in measurements can result from limitations in accuracy
or precision. These limitations can be attributed to systematic errors
and random errors.

Systematic errors are due to the limitations of the measuring
instruments and the skill or carefulness of the experimenter.

Random errors are caused by external factors beyond the control of
the experimenter such as vibrations, noise, changes in atmospheric
pressure and friction.

Accuracy of measurement describes how well the results agree with
an accepted value of the quantity being measured.

Precision refers to the degree of exactness to which a
measurement can be reproduced.

2.3 EQUATIONS; RELATIONSHIPS IN A CAPSULE

On e of the most important and useful ideas in mathematics is
the idea that two variables may be related to each other. This
idea, known as proportion or variation, finds frequent
applications in physical sciences.

2.3.1 Direct Proportion

In direct proportionality, one quantity varies directly as the other
quantity. In symbols, y = kx or k = y where k is the constant of
variation. x
2.3.2 Inverse Proportion
An inverse proportion is on wherein an increase in one quantity
means a decrease in the other. In symbol, y = k or k = xy
where k is the constant of variation. x

2.3.3 Direct Square proportion

In some cases, we can see both quantities are increasing but one
quantity increases faster than the other. This relationship is known as
y
direct square proportion. In symbols, y = kx 2 ork = 2 where k is
the constant of variation. x
2.3.4 Inverse Square Proportion

Another kind of relationship is where one quantity decreases
faster as the other quantity increases. This is known as inverse
square proportion. In symbol, y = k2 or k = x y where k is the
2

constant of variation. x

2.3.5 Manipulating Equations

An unknown variable can be solved by manipulating
equations.

Chapter 1

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