PHYSICS

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