TOPIC 5: APPROXIMATIONS Measurements can be rounded to a certain number of significant figures. Approximation- is a process of rounding numbers to a certain degree of accuracy.A number can be rounded to a certain required place value such as to the nearest ten, hundred, and thousand Rounding Off Numbers Rounding off Whole Numbers to Given Place Values Round off whole numbers to given place values STEPS When rounding a number, stand at the digit of the required place value, then look at the next digit to the right; if it is or more, round up (i.e, increase the digit of…
Author: Msomi Bora
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TOPIC 4: UNITS A unit – is defined as a symbol or sign which is assigned to a number to describe a kind of measurement made Units of Length Convertion of One Unit of Length to Another Convert one unit of length to another The conversion of one unit to another is done by considering the arrangement below Example, from the above we get Computations on Metric Units of Length Perform computations on metric units of length Example 1 Convert Solution Example 2 Three pieces of a string measures 90 dam, 400 m and 25000 cm. Find their total length.…
TOPIC 3: DECIMAL AND PERCENTAGE Decimals The Concept of Decimals Explain the concept of decimals A decimal- is defined as a number which consist of two parts separated by a point.The parts are whole number part and fractional part Example 1 Example 2 Conversion of Fractions to Terminating Decimals and Vice Versa Convert fractions to terminating decimals and vice versa The first place after the decimal point is called tenths.The second place after the decimal point is called hundredths e.t.c Consider the decimal number 8.152 NOTE To convert a fraction into decimal, divide the numerator by denominator To convert a…
TOPIC 2: FRACTIONS A fraction is a number which is expressed in the form of a/b where a – is the top number called numerator and b- is the bottom number called denominator. Proper, Improper and Mixed Numbers A Fraction Describe a fraction A fraction is a number which is expressed in the form of a/b where a – is the top number called numerator and b- is the bottom number called denominator. Consider the diagram below The shaded part in the diagram above is 1 out of 8, hence mathematically it is written as 1/8 Example 1 (a) 3 out of 5 ( three-fifths) = 3/5 Example 2 (b)…
TOPIC 1: NUMBERS We know that when we count we start 1,2 …. . But there are other numbers like 0, negative numbers and decimals. All these types of numbers are categorized in different groups like counting numbers, integers,real numbers, whole numbers and rational and irrational numbers according to their properties. all this have been covered in this chapter Base Ten Numeration Numbers are represented by symbols called numerals. For example, numeral for the number ten is 10. Numeral for the number hundred is 100 and so on. The symbols which represent numbers are called digits. For example the number 521…
TOPIC 7: GEOPHYSICS Geophysics is a branch of science that deals with the physical, chemical, geological, astronomical and other characteristic properties of the earth.It deals with geological phenomena such as the temperature distribution of the earth’s interior, the source, configuration and the geomagnetic field. Structure and Composition of the Earth The Structure of the Earth Describe the structure of the earth The structure of the earth is composed of three major zones arranged in concentric manner. These are crust, mantle and core. The crust Is the outer solid layer o the earth.It is extremely thin(5 to 15km) compared to the…
TOPIC 6: ELEMENTARY ASTRONOMY Introduction to Astronomy The Concept of Astronomy Explain the concept of astronomy Astronomy is a branch of science which deals with the study of origin, evolution, composition, distance and the motion of all bodies and scattered matter in the universe. Universe is the totality of space and time together with matter and energy. Astronomers are the people who deals with the study of astronomy. The Importance of Astronomy in Everyday Life Explain the importance of astronomy in everyday life Importance of astronomy include: It was the earliest method of measuring time. It was used to develop…
TOPIC 5: ELECTRONIC Semi Conductors The Concept of Energy Band in Solids Explain the concept of energy bands in solids In solid-state physics, the electronic band structure (or simply band structure) of a solid describes those ranges of energy that an electron within the solid may have (called energy bands, allowed bands, or simply bands) and ranges of energy that it may not have (called band gaps or forbidden bands). Band theory derives these bands and band gaps by examining the allowed quantum mechanical wave functions for an electron in a large, periodic lattice of atoms or molecules. Band theory has been successfully used to explain many physical properties of…
TOPIC 4: THERMIONIC EMISSION Thermionic emission is the discharge of electrons from heated materials, widely used as a source of electrons in conventional electron tubes (e.g., television picture tubes) in the fields of electronics and communications. The phenomenon was first observed (1883) by Thomas A. Edison as a passage of electricity from a filament to a plate of metal inside an incandescent lamp. The classical example of thermionic emission is the emission of electrons from a hot cathode into a vacuum (also known as thermal electron emission or the Edison effect) in a vacuum tube. The hot cathode can be…
TOPIC 3: RADIOACTIVITY The Nucleus of an Atom The Structure of the Nucleus of an Atom Describe the structure of the nucleus of an atom The word atom is derived from the Greek word ‘atomos’ which means indivisible. The Greeks concluded that matter could be broken down into particles too small to be seen. These particles were called atoms. Atoms are composed of three type of particles: protons, neutrons, and electrons. Protons and neutrons are responsible for most of the atomic mass. The mass of an electron is very small (9.108 X 10-28 grams). Both the protons and neutrons reside in…