TOPIC
1: INTRODUCTION TO PHYSICS
Physics
falls under a broader category of Science. Science is divided into three areas
namely Biology, Physics and Chemistry. The main objective of these subjects is
to study and try to understand the universe and everything in it. The three
subjects are very much interrelated.
Specifically,
Physics is a branch of science that deals with the study of matter and how it
relates to energy. What is matter? Matter
is everything that we see and interact with which has mass and occupies some
space.
In
trying to study the universe, Physicists in most cases endeavor to carry out
experiments where quantities are measured and then collected as data. Such data
and observations made are then used to study any logical pattern(s) to reveal
any relationship between the data. Before the actual experimentation,
propositions can be made which are actually investigated by the experiment.
This is called a hypothesis. The
data is taken through a process of analysis and interpretation and conclusions
drawn. The conclusion may or may not concur with the hypothesis earlier stated.
In case of any pattern between the quantities, this can be expressed in the
form of a law, principle or theory.
A
law is a description of a relationship between quantities that manifests itself
in recurring patterns of events. Some of the laws we will be looking at include
Hooke’s law, Ohm’s law, etc.
A
theory is an explanation of phenomena in terms of most basic natural processes
and relationships. Theories are tentative but can help us affirm already known
laws. When tested and proved, a theory can become a law. A theory that has
survived longer time is assumed to possess some measure of truth.
Physics
as a subject is divided into six broad branches as discussed below:
i.
Mechanics
This
branch deals majorly with motions under the influence of forces. Under this
branch, we look into details the aspects of linear, circular and oscillatory
motions as well as motion of fluids.
ii.
Optics
This
branch takes a keen look at the behavior of light in various media.
iii.
Electricity and magnetism
This
branch looks at the interaction between electric fields and magnetic fields and
the applications of such interactions.
iv.
Thermodynamics
This
branch looks at how heat as a form of energy is transformed to/from other forms
of energy.
v.
Atomic Physics
This
area of study is targeted at the behavior of particles of the nucleus and the
accompanying energy changes.
vi.
Waves
It
deals with the study of the propagation of energy through space.
Physics
does not only relate the remaining two science subjects but also enjoys a
relationship with other subjects as well.
For instance, it is the foundation of technological developmentin any country.
The
study of Physics can open up many avenues of professions including engineering,
degree, diploma or certificate courses.
N/B. Add the relationship between physics and other
disciplines,career opportunities in physics and basic laboratory rules.
TOPIC 2: MEASUREMENTS
2.1: Physical quantities
The study of physics deals mostly with
physical quantities. It involves investigation, making observations, collection
of data and their analysis, interpretation and drawing conclusions.one
important aspect in data collection is taking measurements. When taking
measurements, one must first know the quantity to be measured and the unit for
measuring it.
For
purposes of uniformity, physical quantities have been assigned specific units
which are acceptable world over. These are referred to as International Standard Unit (SI Unit).
Physical
quantities are categorised into two namely basic physical quantities and
derived physical quantities.
A
basic physical quantity is a quantity that cannot be obtained by either
multiplication or division of other basic physical quantities. They are seven
in number. The table below shows the seven basic physical quantities, their
symbols, SI units and the symbols to the units:
|
Basic physical
quantity
|
Symbol of quantity
|
SI Unit
|
Symbol of unit
|
|
Length
|
L
|
Metre
|
M
|
|
Mass
|
M
|
Kilogram
|
Kg
|
|
Time
|
T
|
Second
|
S
|
|
Electric current
|
I
|
ampere
|
A
|
|
Thermodynamic temperature
|
T
|
Kelvin
|
K
|
|
Amount of substance
|
|
Mole
|
Mol
|
|
Luminous intensity
|
|
Candela
|
Cd
|