Pen-Write E-Library

SCHEME OF WORK (NEW)
1 Electric Circuit (DC).

2 Resistors and Cells in Series and Parallel.

3. Electrical Energy and Power

4. Safety Device – Fuse

5. Atomic Structure, Diffusion and Osmosis

6. Crystal Structure of Matter – Amorphous and Crystalline Substances

7. Surface Tension

8. Capillarity

9 Elasticity

10. Energy Stored in an Elastic Material

11. Revision


SCHEME OF WORK (OLD)
WEEK TOPIC
THEME: FIELDS AT REST AND IN MOTION
1. Revision of last term’s work.

2. Description and Property of Fields:(a)Concepts of fields (b) Types of fields (i)Gravitational field (ii)Magnetic field (iii)Electric field (c)Properties of a force field.

3. Gravitational field:( a) Acceleration due to gravity (b)Shape and dimension of the earth.

THEME: ENERGY QUANTIZATION AND DUALITY OF MATTER
4. Particulate Nature of Matter:(a)Structure of matter(i)Evidence of particle nature of matter(ii)Simple atomic structure (b)Molecules (i)Their nature(ii)Size.

5. Particulate Nature of Matter:(c)Crystal structure of matter (d)State of matter: solid, liquid and gas(e)Photons: particle nature of photons.

6. Fluids at rest and in motion:(a)Surface tension-definition and effects (b)Viscosity(c)Applications.

THEME: PHYSICS IN TECHNOLOGY
7. Units of Measurement:(a)Units in industry.

8. Electric field: Electric current, potential difference, Electromotive force, Resistance, types and calculations

9. Electric field: Arrangement of resistors and Ohm’s law, Calculations using Ohm’s law, Electrical energy and power, Continuity faults in electric circuit, Fuse and circuit breaker.

10. Solar collector: Role of the sun in energy production, Solar cell, Solar collector, Construction of a solar panel .

11. Revision.

REFERENCE TEXTS:
1. Senior Secondary School Physics by P.N. Okeke et al. 2011.
2. New School Physics for Senior Secondary Schools by Anyakoha, M.W. 2010
3. Comprehensive Certificate Physics by Olumuyiwa Awe and Okunola, O.O. 2009.
4. Science Teachers Association of Nigeria Physics for Senior Secondary School, Book 1. New Edition; 2012.
5. Melrose Physics for Senior Secondary School, Book 1 by Akano, O and Onanuga, O.O. 2012.

TOPIC: ELECTRIC CIRCUIT
CONTENT: Definition and functions of electric circuit and its components
Definition of some physical quantities in dc circuit
Verification of ohm’s law

Before explaining electric circuit, let us define some terms
1. Conductors: They are materials which allow electrons to pass through them easily e.g. metal, graphite, acids, salt solution etc.

2. Semi conductors: They are materials whose resistivity is mid way between good conductors and insulators e.g. germanium,silicon etc

3. Insulators: They are materials which do not allow electrons to pass through them e.g. paper, plastic, glass, oil, cotton, dry hair, polythene etc

Electric Circuit : An electric circuit is a complete path provided for the flow of electric current. The circuit diagram below is a symbolic representation of such circuit.




Functions of DC circuit components
• cells are chemical devices which produce electric force/pressure that pushes the current to flow.
• Switch / key is a device used to start or stop the current flow.
• Ammeter measures the electric current flowing in a circuit
• Voltmeter measures the potential difference across the terminal of a load
• Rheostat varies the flow of current
• Resistor is a component that limits or regulate the flow of electric current
https://youtu.be/VV6tZ3Aqfuc

EVALUATION
1. Define electric circuit
2. State the functions of the components that make up a circuit



Definitions of some physical quantities

Electric Current (I): it is the measure of the rate of movement (flow) of charged particles along an electrical conductor (a circuit). It is simple electric charge (Q) in motion which consists of moving electrons.

I = Q/t ____________ (1a) where t – time (s)

Q = It ……………… (1b)

Potential Difference (V): Potential difference between two points in a circuit is the work done (W) when one coulomb of charge moves from one point to another.

W = Q (VB – VA) = QV ____________ (2a)

V = W/Q ………………………………(2b)

Electromotive Force (E): e.m.f of a cell is the p.d between the terminals of the cell when it is not delivering any current to the circuit.

Internal Resistance (r): r of a cell is the resistance offered by the electrolyte to the motion of the current.

Resistance (R): R is the ratio of the potential difference (p.d) across the conductor to the current flowing through it. Its unit is the ohm (Ω)

Ohm’s Law
Ohm’s law states that the electric current in a given metallic conductor is directly proportional to the potential difference applied provided that the temperature and other physical factors remain constant i.e V α I
https://youtu.be/HsLLq6Rm5tU

Verification of ohm’s law.
Aim: To show that metallic/ohmic conductor obeys ohm’s law

Apparatus: voltmeter, ammeter, rheostat, battery, key, pieces of wire and ohmic conductor x


Procedure: set up the apparatus as shown above

Observation: As the rheostat is been varied, the reading of the voltmeter is also changing. Also, the current in the ammeter is increasing with increase in potential difference.






https://youtu.be/wvHcm84RsFw

EVALUATION
1. Define the following terms (a) Electric current (b) Potential difference (c) Internal resistance
2. state ohm’s law

General Evaluation
1. State the seven fundamental quantities and their units.
2. State three apparatus each for measuring mass, distance and time

Reading Assignment : Read more on electric circuit – New school physics (pg 77 - 80)

ASSIGNMENT
1. The SI unit of electric current is (a) ampere (b) volts (c) ohm’s (d) coulomb
2. The SI unit of electric charge is (a) ampere (b) volts (c) ohm’s (d) coulomb
3. The SI unit of potential difference is (a) ampere (b) volts (c) ohm’s (d) coulomb
4. The SI unit of resistance is (a) ampere (b) volts (c) ohm’s (d) coulomb
5. Ohm’s law states that (a) V=IR (b) Q=It (c) R=IV (d) W=QV
THEORY
1. Define the following terms (a) Electric current (b) Potential difference (c) Internal resistance
2. Show graphically how the resistance of a resistor can be obtained from a graph.




TOPIC: DESCRIPTION AND PROPERTY OF FIELDS:
CONTENT:
Concepts of fields
Types of fields
(i)Gravitational field
(ii)Magnetic field
(iii)Electric field
Properties of a force field.

CONCEPTS OF FIELDS
A field is a region under the influence of some physical agencies such as gravitation, magnetism and electricity.
There are two types of field:
Vector field
Scalar field.
A vector field is that field which is usually represented by lines of force; while a scalar field is that field that is not represented by lines of force.
Examples of vector fields include gravitational field, magnetic field and electric field.
Examples of scalar fields include regions with distribution of temperature, density, etc.
https://youtu.be/ybNSE8JzJQs

i) Gravitational field
Gravitational field is a region of space or a force field surrounding a body that has the property of mass. In this region, any object that has mass will experience a force of attraction, called gravitational force.
Gravitational force is responsible for the fact that any object thrown up must definitely fall back. This force of gravity pulls every object towards the centre of the earth. That is to say, gravitational force causes a body which is not in contact with the earth to fall to the ground. This therefore means that the earth exerts an attractive force on every object either on it or near it.
Similarly, two objects of different masses exert equal and opposite forces of attraction on each other.
https://youtu.be/7dbRKCIk9ts

The radial field near a planet (e.g, earth) is shown below:

ii) Magnetic Field
Magnetic field is a region around a magnet where it exerts force on other magnets. It is also a region where magnetic force is felt.
The patterns of the magnetic lines of force are shown below:


https://youtu.be/IgtIdttfGVw

MAGNETIC FIELD PATTERN
1. Field of a bar magnet:


2. Attraction between unlike poles:


3. Repulsion between like poles:


iii) Electric Field
An electric field is a region around an electric charge where it exerts force on other charges. It is a field where an electric influence is felt.
The patterns of the electric lines of force are shown below:
1. Isolated positive and negative charge field lines:


2. Attraction between unlike charges:


3. Repulsion between like charges:


https://youtu.be/GgRCkduKCLE

Evaluation:
1. What is a field?
2. State the two types of field.
3. List the examples of vector field.
4. What is neutral point?


PROPERTIES OF A FORCE FIELD.

i) Gravitational Field
The lines of force are directed towards the centre of the planet; hence, it is a radial field.

The gravitational force field (field strength ) ‘g’ at a point is the force per unit mass placed at that point.

i.e, g=F/m in N/kg but the SI unit is m/s2

Any force acting on a body falling towards the centre of the earth is given by F=mg
Gravitational field is a vector quantity.

ii) Magnetic Field
Direction: When a magnet is freely suspended, it comes to rest in the South-North direction of the earth.
Attraction: A magnet has the ability to attract magnetic materials e.g, steel, iron, etc.
Force: A magnet exerts force on other magnets in such a manner that like poles repel and unlike poles attract.
The inseparable nature of poles on the magnetic dipoles: If a magnet is broken into small pieces, however small it may be, it will still have a North and South Poles. The smallest bit of a magnet is a dipole.
Magnetic lines of force originate from the North pole and terminate at the South pole.

iii) Electric Field
Electric lines of force originate from a positive charge and terminate in a negative charge.
Electric lines of force never cross each other.
They repel each other side ways.
They are in a state of tension which tends to shorten them.
The electric field ∈ at a point is defined as the force per unit charge placed at that point.

i.e,∈=F/q measured in Newton per Coulomb N/C
https://youtu.be/LDJwqxpzA7A

Evaluation:
1. State two properties each of the three vector fields discussed.
2. What is the direction of the magnetic lines of force?
3. What is the unit of electric field strength?

GENERAL EVALUATION:
1. Discuss the properties of the magnetic flux.
2. Define the electric field strength.
3. Itemize the three vector fields.
4. Why is electric lines of force a vector quantity?

ASSIGNMENT:
1. The following are scalar quantities. Except ---
Time
Temperature
Magnetic flux
Mass
2. Which of the following statements best describe a neutral point?
A region around a field where there is a greater influence due to the field.
A region around a field where there is no effect.
A region outside the field concern.
A region experiencing less amount of the field’s effect.
3. The following are examples of vector field. Except ---
Magnetic field
Electric field
Density field
Gravitational field
4. Which of the following statement(s) is/are correct?
Like poles attract.
Like poles repel.
Unlike charges repel.
Unlike charges attract.
i & ii
i & iv
ii & iv
ii & iii
5. The following are properties of electric field. Except ---
Electric lines of force originate from a positive charge and terminate in a negative charge.
Electric lines of force do cross each other.
They repel each other side ways.
They are in a state of tension which tends to shorten them.

Essay
1.With the aid of diagrams, carefully explain the electric and the magnetic lines of forces.
2. What is a neutral point?

READING ASSIGNMENT
Read up the topic: ‘’Acceleration Due to Gravity & The Earth’s Shape’’ in the following text books.
Senior Secondary School Physics by P.N. Okeke et al.
New School Physics for Senior Secondary Schools by Anyakoha, M.W.

TOPIC: RESISTORS & CELLS CONNECTED IN SERIES & PARALLEL
CONTENT: Resistors in series and parallel
Cells in series and parallels

Resistors in series: These are end to end connection.


Characteristics
 Same current flow through each resistor IT= I1 = I2 =I3

 Potential difference across each resistor is different V1 ≠ V2 ≠V3

 P.d are additive VT= V1 + V2 +V3

 Power are additive

 Applied voltage equals the sum of different p.d VT= V1 + V2 +V3

 Resistance are additive.

RT = R1 + R2 + R3 _______ for 3 resistors

RT = R1 + R2 + R3….. + Rn ___ for n numbers or resistors

https://youtu.be/pd3RkGs1Tsg

Resistors in parallel: These are side by side connection.

Characteristics
 Different resistors have their individual current

 P.d across each resistor is the same VT= V1 = V2 = V3

 Branch current are additive IT = I1 + I2 +I3

 Conductance are additive

 Power are additive




https://youtu.be/5uyJezQNSHw

EVALUATION
1. Differentiate between resistors connected in series and parallel
2. State the relationship between resistance and conductance



Cells in series: end to end connections
ET = E + E + E = 3E
For n cells; ET = n E
ET = E1 + E2 + E3

Cells in parallel: side by side connections

ET = E+E+E/3 = 3E/3 = E

Calculations
• if 2Ω, 3Ω, and 5Ω resistors are connected in (a) series (b) parallel, calculate the equivalent resistance
(a) RT = 2+3+5 = 10Ω

(b) 1/RT = 1/2 +1/3+1/5 = 15+10+6/30 = 31/30

RT = 30/31Ω

https://youtu.be/crdHdmIzRQU

https://youtu.be/Vbm4SEclhD0

EVALUATION
1. If 2Ω, 2Ω, and 1Ω resistors are connected in (a) series (b) parallel, calculate the equivalent resistance
2. Calculate the potential difference across a resistor of resistance 2KΩ that allows a current of 1mA to pass through it

Reading Assignment : Read more on series & parallel connections of resistors & cells – New school physics (pg 79)

General Evaluation:
1. State four types of motion and give an example each
2. What is the cause of motion.?

ASSIGNMENT
1. If four identical cells each 2volts are connected in series, the equivalent pd is ……… (a) 2v (b) 4v (c) 6v (d) 8v
2. If four identical cells each 2volts are connected in parallel, the equivalent pd is ……… (a) 2v (b) 4v (c) 6v (d) 8v
3. If 2Ω, 2Ω, and 1Ω resistors are connected in series the equivalent resistance (a) 5 Ω (b) ½ Ω (c) 4 Ω (d) 2 Ω
4. If 2Ω, 2Ω, and 1Ω resistors are connected in parallel the equivalent resistance (a) 5 Ω (b) ½ Ω (c) 4 Ω (d) 2 Ω
5. Two resistors of resistance 1 Ω are connected in parallel to a 2 Ω resistor, the equivalent resistance is …….. (a) 4 Ω (b) 3 Ω (c) 2 Ω (d) 1 Ω
THEORY
1. A battery of 15v and internal resistance 5Ω is connected to a resistor 0f 20Ω.
Calculate the value of (a) electric current (b) terminal voltage (c) lost voltage.
2. If 8c of charge passes through a wire at a steady rate in 2s. calculate the Current.





TOPIC: Gravitational field:
CONTENT:
Acceleration due to gravity
Shape and dimension of the earth.

ACCELERATION DUE TO GRAVITY
When an object is dropped from the top of a hill or even a tree, the body moves and increases in velocity until it touches the ground with a finite value. Such movement is influenced by the earth’s gravitational field. The increase in velocity is therefore due to acceleration due to gravity which is usually represented by ‘g’. The motion of such body under gravity is always described as motion under free fall.

However, when two bodies of different masses are released from a height above the ground level, they do hit the ground at the same time. This is because the body with bigger mass will have a bigger weight and thus, larger amount of inertia, making it to fall with the same constant acceleration as the body with smaller mass.

This constant acceleration, called acceleration due to gravity has a value of 9.8m/s2 or 10m/s2.

When a body is released from a height so that it falls towards the centre of the earth, ‘g’ is positive; but when a body is thrown upward, it goes against ‘g’ thereby decreasing in velocity until it momentarily comes to rest at the maximum height. For upward movement, ‘g’ is negative.

The equations connecting acceleration due to gravity, ‘g’ are as follows:

For downward movement, v2=u2+2gs and s=ut+½ gt2

For upward movement, v2=u2-2gs and s=ut-½ gt2

When a body is released from rest at a certain height so that it falls towards the centre of the earth,



This equation shows that the time to reach the ground does not depend on the mass of the object.

Determination of Acceleration Due to Gravity
The value of ‘g’ could be determined using:
Formula method: A body is released from a height ‘s’ and the time t is taken; then use s=½ gt² to get the value of ‘g’.
Simple Pendulum Experiment method: The value of ‘g’ could also be determined using this experiment.
The period T for the oscillation is given by:

(NB: Educator should carry out the two experiments with the students).
https://youtu.be/hV2MwaMApZw
https://youtu.be/kIasiNg1-fA

Evaluation:
1. What is the value of acceleration due to gravity?
2. What is the mathematical relationship between the period of oscillation T and the length of the string used l in a simple pendulum experiment?



SHAPE AND DIMENSION OF THE EARTH.


The earth is one of the nine planets in the solar system. It is spherical is shape. It is also divided into two hemispheres – the Northern and Southern hemispheres. There are two major types of lines that run through the earth. They include:
The latitude lines and
The longitude lines
The latitude lines are imaginary lines running from the east to the west, north or south of the equator. This means that they increase towards the North or South. Examples are:
Tropic of cancer
Tropic of capricon
Artic circle
Antartic circle.
The equator line on zero degree 0°
The longitude lines are imaginary lines running from the North pole to the South pole, east or west of the Greenwich meridian. They increase towards the east or west. E.g, the Greenwich meridian on zero degree 0° running through Ghana and London.

However, the earth has a radius of approximately 6400km.

https://youtu.be/UgnPLaLGQsI

Evaluation:
1. State two differences between latitude lines and longitude lines.
2. Mention two examples of the lines of latitude.
3. What is the approximate radius of the earth?

GENERAL EVALUATION:
1. What is the slope when T^2 is plotted against l in the simple pendulum experiment?
2. Why does the velocity of a body thrown upward decreases till it reaches the maximum height?
3. What happens to the final velocity at the maximum height attained during the upward movement?
4. What is the shape of the earth?
5. How many hemispheres has the earth?

ASSIGNMENT:
1. The weight of a substance slightly varies from place to place. This is because ---
There is a slight variation in the value of ‘g’ towards the poles on the surface of the earth.
The weight of a substance can not be the same throughout the surface of the earth.
Of the rotation of the earth.
The amount of stuff contained in a substance can not be the same throughout the surface of the earth.
2. Which of the following is not a latitude?
Tropic of cancer
Tropic of capricon
Artic circle
Greenwich meridian
3. In the simple pendulum experiment, a graph of T^2 against L will give a slope value of ---
(4π²)/g
g/4π
4π² g
2π√l
4. The equation for a period in a simple pendulum experiment is ---
T=4π√(l/g)
T=2π√(l/g)
T=2π√(l/2g)
T=2π√(2l/g)

Essay
In a simple pendulum experiment, the time taken for 20 counts oscillations is 49s. What is the period for the oscillation? Also find the length of the string used. (Take g=10m/s², π=3.14)

READING ASSIGNMENT
Read up the topic: ‘’Particulate Nature of Matter’’ in the following text books.
Senior Secondary School Physics by P.N. Okeke et al.
New School Physics for Senior Secondary Schools by Anyakoha, M.W.

TOPIC: PARTICULATE NATURE OF MATTER:
CONTENT:
Structure of matter - Evidence of particle nature of matter
Simple atomic structure
Molecules -Their nature & Size.

STRUCTURE OF MATTER
Matter can be defined as anything that has mass and occupies space. All substances are made up of matter and are all acted upon by gravitational force towards the centre of the earth.

When a matter such as a piece of yam is cut into smaller and smaller bits, one would eventually find the smallest particle which could not be divided further. Such particles are called molecules.
Matter can exist in the following states:
Solid state
Liquid state and
Gaseous state.


Evidence of Particle Nature of Matter
The fact that matter is made up of particles is evident from the phenomena of diffusion and Brownian motion.
The random motion of particles such as smoke as a result of being bombarded by invisible air molecules is known as Brownian Motion.
Diffusion is the process by which substances mix thoroughly, together and intimately with one another as a result of the random motion of their molecules. The direction of the molecules is in such a way that they flow from the region of higher concentration to the region of lower concentration. Diffusion is fastest in gaseous state and least in solid state.

The rate of diffusion is affected by the following factors:
Mass of the molecules
Temperature
Density
Pressure
Concentration gradient
Other evidences of the particulate nature of matter are osmosis (the movement of molecules from a region of lower concentration to a region of higher concentration across a thin permeable membrane), and law of definite proportion.
https://youtu.be/SYu4Shci_3Q

Evaluation:
1. On what condition will a body be considered a matter?
2. In what state of matter is diffusion a) fastest b) slowest?
3. What is the direction of flow of molecules during diffusion?




SIMPLE ATOMIC STRUCTURE


An atom is defined as the smallest unit of matter that can take part in a chemical reaction and is not capable of independent existence.

Every atom of a substance is believed to have a nucleus of about 10-15m in diameter. The nucleus of an atom contains neutron and proton, called the nucleons.

A nuclide is a particular species of atom, one whose nucleus contains a specified number of protons and neutrons.

The atomic number Z (when an element A/ZX is considered), is the number of protons contained in the nucleus. This is equal to the number of electrons in a neutral atom of the element.

The mass number A is the number nucleons (protons plus neutrons) in the nucleus.

Isotopes are nuclides having the same atomic number but different mass number. E.g, 17/35Cl, 17/37Cl

Isobars are nuclides having the same mass number but different atomic number. E.g 18/40Ar, 20/40Ca


The below table summarizes the properties of the elementary particles in the atom of an element.



The important points to keep in mind are as follows:
Protons and neutrons have almost the same mass, while the electron is approximately 2000 times lighter.
Protons and electrons carry charges of equal magnitude, but opposite charge. Neutrons carry no charge (they are neutral).
https://youtu.be/h6LPAwAmnCQ

Evaluation
1. What are the elementary particles contained in the nucleus of an atom?
2. Write down their masses and charges.
3. Which particle is located in the outermost shell?


MOLECULES -THEIR NATURE & SIZE
All matter is made up of tiny particles called molecules. These molecules themselves are made up of tinier particles called atoms. Both molecules and atom are too tiny to be seen with the naked eyes.

One mole of every substance is believed to contain about 6.02×1023 molecules. One molecule of a substance could be found from the combination of two or more elements of that substance.
Hence, we define a molecule as ‘’ the smallest unit of matter that is capable of independent existence’’. This means that a molecule of a substance could exist alone.
An atom is defined as the smallest unit of matter that can take part in a chemical reaction and is not capable of independent existence.
An element is any substance in which everything could be built up. It is a substance which consists of only one kind of matter and cannot be broken down into anything simpler by any chemical means.

https://youtu.be/FsS0nLKoaoo

Evaluation:
Define the following terms.

1. Molecule
2. An atom
3. An element.
4. Which of the above is capable of dependent existence?
5. Which of them is capable of independent existence?

GENERAL EVALUATION:
1. Differentiate an atom from a molecule.
2. Highlight the states of matter.
3. Enumerate the factors capable of influencing diffusion rate.
4. What were the evidences to prove the particulate nature of matter?

ASSIGNMENT:
1. The following are elementary particle, except ---
A.Electron
B.Nucleus
C.Neutron
D.Proton
2. In a neutral atom of an element,
A.The quantity of electron at the orbit outnumber that of the proton in the nucleus.

B.The electron has no charge but has a relative mass of 1/1840 .

C.The number of proton in the nucleus equals that of the electron in the outermost shell.

D.The charge on the proton equals that of the neutron in the nucleus.
3. Which of the following is the correct mass value for an electron?

A.9.110 x 10-31g

B.9.110 x 10-30 kg

C.6.110 x 10-31 kg

D.9.110 x 10-31 kg
4. One of the below is capable of independent existence.
A.Atom
B.Element
C.Molecule
D.Compound

5. Considering the element, P/QR, ‘P’ represents ---

A.Atomic number.
B.Mass number.
C.Number of proton
D.Non of the above.
Essay
1. Briefly discuss the atomic structure.
2. Make a distinction between an isotope and an isobar.

READING ASSIGNMENT
Read up the topic: ‘’Crystal Structure of Matter’’ in the following text books.
Senior Secondary School Physics by P.N. Okeke et al.
New School Physics for Senior Secondary Schools by Anyakoha, M.W.

TOPIC : ELECTRICAL ENERGY AND POWER
CONTENT : Electrical Energy
Electrical Power
Buying Electrical Power

Electrical Energy
Energy = Work (Joules)
W = QV_______________________(1)

But Q = It

W = VIt ______________________(2)

From ohm’s law V = IR
W = I²Rt______________________(3)

From ohm’s law I = V/R
W = V²t/R_____________________(4)

W = QV = VIt = I²Rt = V²t/ R

Electrical Power
Power = work done/time taken (watt) __ (5)

P =QV/t = VI = I2R = V2/R…………….(6)

https://youtu.be/mc979OhitAg

EVALUATION
1. The headlamp of a car takes a current of 0.4A from a 12v supply. Calculate the energy produced in 5 minutes.
2. State four factors that affect the resistance of a conducting wire.

Buying of Electrical Energy
Commercial power is consumed in kilowatt- hour (kWh)
NB 1kwh = 3.6 х106 J = 3.6MJ
Cost = Pct/ 1000………………………….(7)
P – Power (w) NB : P(W)/ 1000 = P (KW)
c – Cost per kWh (unit) it means that it is in kWh
T – Time (hr)
https://youtu.be/SMPhh8gT_1E

EVALUATION
1. Find the cost of running two 100w amplifier, ten 50w television and twenty 60w lamp for 24hrs, if the electrical energy cost 60k/unit
2. A landlord has eight 40w electric lighting bulb, four 60w bulb and two 100w bulb. If he has all the point on for 5hrs, what is the bill for 30 days?

Reading Assignment : Read more on electrical energy & power – New school Physics (pg 81-82

Genaral Evaluation:
1. Define frictional force
2. Give three ways of reducing friction.

ASSIGNMENT
1. Electrical energy is measured in (a) watt (b) kilowatt-hour
(c) kilowatt (d) none of the above
2. If a p.d of 240v is applied across a lamp that supplies energy at the rate of 60w
What is the value of current? (a) 0.2A (b)0.25A (c) 0.3A (d) 3A
3. The resistance of the filament in question 2 is ______ (a) 96Ω (b) 48Ω
(c) 960Ω (d) 900Ω
4. Calculate the conductance of a conductor having a resistance of 10Ω
(a) 0.1 (b) 1 (c) 10Ω (d) 0.01Ω
5. The SI unit of resistivity is ____ (a) Ω/M (b)Ω2/M (c) ΩM
(d) none of the above.
THEORY
1. Find the cost of running two 100w amplifier, ten 50w television and twenty 60w lamp for 24hrs, if the electrical energy cost 60k/unit
2. A landlord has eight 40w electric lighting bulb, four 60w bulb and two 100w bulb. If he has all the point on for 5hrs, what is the bill for 30 days If electric energy cost 80k per KWhr.




TOPIC: PARTICULATE NATURE OF MATTER (CONT’D)
CONTENTS
1. Crystal structure of matter
2. Crystalline and amorphous substances
3. The three state of matter ( solid, liquid and gaseous)
4. Photons (particle nature of photons)

Crystal structure of matter
A crystal is a solid matter that has definite melting point and definite characteristic shape irrespective of the size. In any crystal, the atoms, molecules or irons are arranged in definite repetitive pattern or lattice. Substances which have the same crystalline shape are said to be isomorphous. This implies that crystalline substances exist in different shapes. For example, sodium chloride crystals have cubical shape. Other crystals shapes are; prismatic and octahedral shapes. See diagrams below.


The basic unit of a crystal is called unit cell. If these unit cells are packed up and down, side by side, in all directions, a cubic lattice will emerged. The atoms or molecules or ions are placed at the corners of the unit cells stacked side by side, up and down like building blocks. This is the structure of sodium chloride (NaCl). In sodium chloride crystal structure, the atoms of (Na) and (Cl) are arranged such that the atoms take alternate positions in the cube. Each atom within the crystal has six immediate neighbours. The chloride ions (Cl-) are larger than the sodium ions (Na+). Since their charges are opposite, they are held together by strong electrostatic forces.


https://youtu.be/iyJvxOLq02s
Other types of unit cells are; face-centred cubic (FCC) and the body centred cubic (BCC) crystals.

1. Face-centred cubic crystals:
These crystals have identical atoms at each of the corners and different atom or ion at the centre of each of the faces as shown in Zinc Sulphide (ZnS) unit cell below.


2. Body-Centred cubic crystals
Crystals that fall into this group are: Chromium, ion and platinum salts. In these crystals, the unit cell has identical atoms or ions at each corner and one different atom or ion at the centre of the unit cell as shown in the diagram below.


https://youtu.be/HCWwRh5CXYU

Evaluation
1. What is a crystal?
2. What is meant by crystal lattice?
3. Differentiate between body-centred cubic crystals and face-centred cubic crystals



Crystalline and Non-crystalline or Amorphous Substances
Non-crystalline or amorphous substances do not have definite shape because their atoms are not regularly arranged like that of crystalline substances. These substances behave more like liquids than solids. Examples of non-crystalline substances include: glass, plastics, tar, e.t.c. the molecules of these substances are long-chain and are inter twined in the liquid state as shown below.


Note: Crystalline substances have high melting points because much heat is required to break the strong intermolecular forces binding the molecules together.
https://youtu.be/RyIARZ8jG1c

Differences between amorphous and crystalline substances

https://youtu.be/SQMrki3uX2s


State of matter
Matter exists in three states, these are; Solid state, liquid state and gaseous state. In the solid state, the molecules are closely packed and held together by strong intermolecular forces. The molecules do not move because of these strong intermolecular forces. They can only vibrate about their mean positions. This accounts for why solids have definite shape and do not move easily. In the liquid state, the intermolecular distances are greater and the molecules are also held together by forces which are not as strong as those holding the molecules of solids. For this reason, the molecules have some degree of freedom to move. This is the reason why liquids move and change shape easily. In gaseous substances, intermolecular distances are the farthest and the intermolecular forces between the molecules are so weak that the molecules move freely. The kinetic energies of these molecules are greater than that of solids and liquids. That is why gases move fast and randomly. The table below gives the characteristics of the three states of matter.

https://youtu.be/MrTxRn9MNWM


Evaluation
1. Distinguish between crystalline and amorphous substances
2. Give 3 characteristics each of solids, liquids and gaseous substances

Assignment
1. Reading assignment: Read on surface tension and viscosity
2. Draw the crystal structure of NaCl2

TOPIC: SAFETY DEVICE – FUSE
CONTENT : Fuse
Types of Fuse
Detecting Fault in a Circuit
Fuse
Fuse is a protective device, designed to melt at the passage of excess electric current through it. It can also be defined as a device for opening circuit, by means of a conductor designed to melt when an excessive current flows along it. The conductor actually designed to melt is called fuse element.

Fuse element is the part of the fuse that is designed to melt and then open the cct

Current rating of a fuse : it is the minimum current which the fuse will carry for an indefinite/ unlimited period without deterioration of the fuse element

Fusing current: is the minimum current that will cause the fuse element to heat up and melt/ rapture or blow.

Fusing factor is the ratio of the fusing current upon the current rating.

Fusing factor = fusing current/ current rating
https://youtu.be/BLIYsRwKrkE

Types of Fuse
 Re-wireable fuse
 Cartridge fuse
 High breaker capacity fuse
 Others
Detecting Fault in Electric Circuit
 Merger tester – insulation resistance test
 Test bell – polarity test
 Earth-loop impudence tester – test for earthling
 Continuity tester – test for continuity
https://youtu.be/kuthVyWHwqE

EVALUATION
1. Define the following terms (a) fuse (b) fuse element (c) current rating of a fuse
2. State the relationship between fusing factor, fusing rating and current rating
3. List three types of fuse
4. Mention four ways of detecting fault in an electric circuit

Reading Assignment : Read more on safety devices – New school physics (pg 83-84)

General Evaluation:
1. Define the term scalar and vector quantities. Give two examples each
2. A rectangular box of dimension 6cm x 10cm x 2cm weighs 15N. Calculate the density of the density of the box.


ASSIGNMENT
1. Fuse is a protective device, design to ……….. (a) stick (b) melt (c) disappear (d) repel
2. The conductor designed to melt is called ……. (a) fuse element (b) fuse (c) resistor (d) cartridge fuse
3. The following are examples of fuse except ……. fuse (a) re-wire able (b) merger (c) cartridge (d) high breaking capacity
4. Which of the following correctly gives the relationship between linear speed v & angular velocity w of a body moving uniformly (a) v=w r (b) v=w2r (c) v=wr2 (d) v=w/r
5. The motion of the prongs of a sounding turning fork is (a) random (b) translational (c) rotational (d) vibratory
THEORY
1. Define the following terms (a) fuse (b) fuse element (c) current rating of a fuse
2. Mention four ways of detecting fault in an electric circuit.





TOPIC: FLUIDS AT REST AND IN MOTION
CONTENTS
1. Surface tension-definition and effects
2. Viscosity
3. Applications

Surface tension-definition and effects
Surface tension can be defined as the force per unit length normal or perpendicular to a line on the surface of a liquid. In order to understand the origin of surface tension, we need to define two terms namely; force of cohesion and force of adhesion.
Force of cohesion is the force of attraction existing among molecules of the same substance while force of adhesion is the force of attraction that exists between molecules of different substances. These forces can be used to explain why water wet glass and mercury does not.
The force of adhesion of water molecules to glass molecules is stronger than the force of cohesion of water molecules. This makes water to wet the glass when it is spilled on it. The force of cohesion of mercury molecules is greater than the force of adhesion between mercury and glass molecules. Hence, when mercury is spilled on glass, it does not wet the glass but forms spherical droplets. For the same reason, the water surface in a glass vessel is convex while the mercury in a glass vessel is concave.
Surface tension exists because of the molecular attraction between the liquid molecules. Consider a vessel of water with molecules P and Q as shown in the figure below.


Q is attracted by equal number of molecules all around and so it is in a state of equilibrium. Molecule P is nearer the surface of the liquid than Q. Therefore part of its sphere of molecular attraction is in the air and part is in the liquid. Since the liquid has much more molecules than the air, Q will be attracted towards the liquid by many more molecules than towards the air. The resultant force on Q will be towards the liquid, hence tension exists on the surface of the liquid.
https://youtu.be/zMzqiAuOSz0

Experiment to demonstrate surface tension
Apparatus: Beaker, water, steel needle, filter paper and grease.
Procedure:
1. Apply the grease to the steel needle so that water will not wet it and place it on the filter paper
2. Carefully place it on the water surface

Observation:
The paper will absorb water and eventually sinks to the bottom of the beaker leaving behind the needle floating on the water provided the water is not disturbed. The water surface will also be depressed under the needle. The needle floats on the water surface due to surface tension.

https://youtu.be/PFZsMe4Vr58

https://youtu.be/b_UnAsmPwSw

Surface tension can be reduced by
1. Increasing the temperature of the liquid
2. Adding soap or detergent to the liquid
3. Adding alcohol
4. Adding camphor

Effects of surface tension
1. Ants and pond skaters are able to move on water surface because of surface tension
2. Small objects like razor blade and needle can be made to float on water when carefully placed as a result of surface tension
3. Mercury forms spherical droplets when spilled on glass because of surface tension
4. The hairs of a paint brush spread out and come together when dipped in clean water and removed respectively as a result of surface tension
5. water drops slowly from a loosely closed tap as a result of surface tension
6. the rise and depression of liquid in a narrow tube is as a result of surface tension
https://youtu.be/rCU9E-dbRhk

Evaluation:
1. Define surface tension
2. Mention some effects of surface tension



Viscosity
Viscosity by definition is internal friction between layers of fluids in motion. Liquids are dense pour more slowly than those that are less dense. E.g honey will pour more slowly than water because it is denser than kerosene. This means that honey is a more viscous liquid than water. Viscosity can be demonstrated if we consider a ball bearing falling through some liquids.


Experiment to demonstrate viscosity
Apparatus: beaker, two different liquids say, engine oil and kerosene
Procedure: pour the engine oil into the beaker and drop the ball bearing into it. Observe the ball bearing as it moves to the bottom of the beaker. Do the same thing using the other liquid (kerosene). You will observe that the ball bearing gets to the bottom of the beaker much earlier than it does in engine oil. Therefore viscosity in engine oil is higher than that in kerosene.
https://youtu.be/2Gdxu4XcsbY

https://youtu.be/f6spBkVeQ4w

https://youtu.be/ubGxkWWWiIg


Terminal velocity
A ball that is made to fall through a liquid is under the influence of three forces namely; its weight (W = mg) that acts vertically downwards, the upthrust (U) of the liquid on the ball acting upwards and the viscous force (v) opposing it motion. The resultant force acting on the ball can be written as
ma = W – v – U where ‘a’ is the acceleration of the ball through the liquid and m is the mass of the ball. At a certain time in the motion of the ball, its velocity becomes uniform or constant. At this stage acceleration ‘a’ is 0 so that the above equation becomes
W – v –U = 0 or
Mg – v –U = 0
v = mg – U
The velocity-time graph of the motion of the ball is given as shown below




Applications of surface tension and viscosity
1. The knowledge of surface tension is applied in industries in making some materials such as, umbrellas, canvass, rain coats and waterproof tents
2. It is difficult to wash dirty clothes or oily clothes with water only. That is why we use soap and detergents to wash. Soap and detergents weakens the surface tension of water and enables it to float away dirt or oil from the material
3. Viscous liquids are used as lubricants. Examples are grease and engine oil.
4. Viscosity is applied in the design of boats, ships and aircraft.
https://youtu.be/2XPWx_P4o2s

Evaluation:
1. Differentiate between viscosity and surface tension
2. Give two applications each of viscosity and surface tension



Assignment
1. Reading assignment: Read on various units of measurements in industries
2. Consider at least four different liquids. E.g palm oil, ground nut oil, engine oil, e.t.c and test their degree of viscosity as was done earlier using a suitable ball bearing. Now answer these questions
i. In which liquid did the ball travel fastest?
ii. Which liquid did the ball travel slowest?
iii. Hence, list the liquids in their order of viscosity starting from the lowest to the highest.
3. Mention two other low viscous liquids and two other high viscous liquids.

TOPIC: MATTER, ATOMIC STRUCTURE, STATES OF MATTER, DIFFUSION, OSMOSIS, BROWNIAN MOTION
CONTENT : Atomic Structure
Molecular Theory of Matter
Diffusion and Osmosis
Matter
Matter is defined as anything that has mass and occupies space. All substances are made up of matter. It exists in three states namely, solid liquid and gas. Examples of solids are ice, brick, metal, concrete, wood etc. examples of liquid are water, milk, oil etc while that of gas are oxygen, nitrogen, CO2
https://youtu.be/Vt8-ndOGSUk

Structure of Matter
Matter is made up of discrete particles namely atom, molecules and ion.
(i) Atom: An atom is the smallest particle of an element which can have a separate existence. Atom is made up of a nucleus and a revolving electron around an orbit or shell. The nucleus consists of proton and neutron. The proton is positively charged, electron is negatively charge and neutron is neutral (i.e. has no charge). The number of protons equates the number of electrons .An atom that contains the same number of protons and electrons is said to be electrically neutral.

(ii) Molecule: A molecule is a group of atoms of the same or different elements joined in simple proportion. They come together to make up matter

Brownian Motion
 Molecules exist
 Molecules are continually in motion
https://youtu.be/OjElFVfHdWs

EVALUATION
(1) Explain the structure of matter
(2) What is the importance of Brownie’s motion

Molecular Theory of Matter
Using kinetic theory explain the (i) definite structure of solid (ii) shape of liquid (iii) gas
https://youtu.be/yg9OjhSlmBk
(i) Solid: Matter consists of molecules which are tightly held together by intermolecular forces to make the molecules to vibrate about their mean positions, giving the solid definite shape. If the solid is heated, the total energy is divided among the molecules to make them vibrate faster. Eventually, they move so fast that they break loose from their fixed position.

(ii) Liquid: The molecules of a liquid can move about within the given volume of the container. Hence, liquid has its own size but no shape. If the liquid is heated, its molecules gain kinetic energy and move faster, until eventually molecules can escape from the surface. The liquid then vanishes and turns to gaseous state.

(iii) Gas: The molecules of a gas are also in constant motion like the liquid but comparatively far apart. They move at high speed, colliding with one another and with the walls of their containing vessel. They fill the vessel and exert pressure on the walls of the container. The pressure of the gas is caused by the collision of the molecules with the walls of the container.

https://youtu.be/R1l1Cww88XQ

https://youtu.be/N9OL6AwyM5I

Diffusion and Osmosis
Diffusion: Diffusion is the process by which different forms of matter (fluids) mix intimately with one another owing to the kinetic nature of their molecules. It is also the tendency of a gas to mix with another and fill an empty space as a result of the constant random motion of the molecules.
https://youtu.be/eGCQwvIndMU
The rates of diffusion or factors affecting diffusion are (i) density (ii) mass (iii) temperature (iv) pressure (v) concentration
Also, Graham’s law of diffusion states that at constant temperature, gas diffuse at rates inversely proportional to the square root of their vapour densities.


(ii) Relative molecular mass is twice its vapour density

Osmosis: This is the movement of water molecules from the region of higher concentration to a region of lower concentration through a semi-permeable membrane.
https://youtu.be/PRi6uHDKeW4

https://youtu.be/Xxp6oponwkg

EVALUATION
1. Using kinetic theory, explain the definite structure of solid
2. State four factors that affect the rate of diffusion
Reading Assignment : Read more on atomic structure, diffusion and osmosis – New school physics (pg 87-92)

General Evaluation:
1. State Archimedes principle
2. State the law of floatation

ASSIGNMENT
1. The following are examples of theory except (a)concrete (b) oil
(c) brick (d) metal
2. The nucleus of an atom consist of (a) proton and electron (b) neutron and
electron (c) proton and neutron (d) none of the above
3. Positive ions are called ____ (a) camions (b) anions (c) molecules
(d) atom
4. When is atom said to be electrically neutral (a) when the number of proton
equals the number of neutron (b) when the number of protons equals the
the number of electrons (c) when the number of proton is greater then the
number of electron (d) when the number of neutron equals the number of
electron
5. ion is a form of ____ (a) atom (b) molecules (c) matter
(d) none of the above.
THEORY
1. Using kinetic theory, explain the definite structure of solid
2. State four factors that affect the rate of diffusion




TOPIC: CRYSTAL STRUCTURE OF MATTER- AMORPHOUS AND CRYSTALLINE SUBSTANCES.
CONTENT : Crystal Structure
Crystalline and Amorphous Substance

Crystal Structure
The term crystal structure is generally used to describe the internal structure of solids. The particles of a solid are orderly arranged in parallel planes. In other words, solid crystals consist of particles arranged in parallel planes. Crystals are built up from simple structural units called unit cells. A unit cell (also called a space lattice) is made up of few atoms, ions or molecules.

There are seven types of unit cells. Each type gives rise to a crystal system. They include cubic, rhombic, monoclinic, triclinic, tetragonal, rhombohedra and hexagonal crystal system. X- ray analysis of crystal shows that three pairs of opposite parallel faces bund the unit cells in all crystal systems, except in hexagonal system. We can draw three imaginary lines between the centres of the opposite parallel faces.
These imaginary lines represent three axes of symmetry. The length of these axes of symmetry and the angles between them determines the system to which a crystal belongs. This is demonstrated using cubic and monoclinic crystal systems.

In a cubic crystal system, the axes of symmetry have equal length and at right angles to each other. This type of crystal system is found in copper, sodium chloride, silver, gold, iron, sodium, potassium etc. however, the type of cubic crystal system found in copper, silver, gold and sodium chloride is different from the type found in sodium, iron and potassium. The former is called face centred cubic, while the later is called body centred cubic. In a monoclinic system, the axes are not equal in length and only two of them are at right angles to each other. These crystal systems are in sugar, washing soda, ferrous sulphate etc.




EVALUATION
1. What is a unit cell?
2. With the aid of diagram, distinguish between cubic crystal system and monoclinic crystal system.



DIFFERENCES BETWEEN CRYSTALLINE AND AMORPHOUS SUBSTANCES
On the basis of internal structure of solid, we can classify a solid as either a crystal substance (e.g. common salt) or an amorphous substance (e.g. glass). The differences between the two substances are:


https://youtu.be/RyIARZ8jG1c

https://youtu.be/tbJy8Pap-_A
EVALUATION
1. Differentiate between crystalline and amorphous substances
2. Define crystal lattice
Reading Assignment : Read more on crystal structure of matter – New School Physics (pg99- 101)

General Evaluation:
1. A body of mass 25Kg moves on a horizontal straight road with a velocity of 15m/s. calculates the height above the road at which it possesses a potential energy equal to its kinetic energy. [g= 10m/s2]
2. An engine of a car of power 80KW moves on rough road with velocity 32m/s the force required to bring it to rest is?

ASSIGNMENT
1. Crystal structure is generally used to describe (a) the external structure of solids (b) the internal structure of solids (c) the internal structure of liquids (d) the external structure of liquids
2. Particles of a solid are orderly arranged in .,……….. planes (a) parallel (b) horizontal (c) vertical (d) none of the above
3. Unit cell is also known as (a) monoclinic system (b) polyclinic system (c)space lattice (d) none of the above
4. ………… substance has a definite internal arrangement of particles (a) Amorphous (b) Crystalline (c) Elastic (d) Atomic
5. ………….. are not efflorescence substance (a) Amorphous (b) Crystalline (c) Elastic (d) Atom
THEORY
1. Differentiate between crystalline and amorphous substances
2. Define crystal lattice




TOPIC: UNITS OF MEASUREMENTS IN INDUSTRIES
CONTENTS
Measurement of length
Measurement of volume
Measurement of temperature / power

Measurement of length
Length was considered earlier as a fundamental quantity whose S.I unit is metre. We also learnt that other units of length are centimeter, millimitre,, and kilometer. There exist other units of length which have been in use long ago and are still being used today. Such units are; a foot ( feet for plural). It is equal to 12 inches another unit of length which is about 30cm. others are, yards, furlongs and miles. The table below shows some of these units and their conversions to S.I unit
https://youtu.be/ZNX-a-5jGeM

Units of length
Multiples of other units Other units Conversion to S.I unit
--------------- 1 inch = 2.54cm = 0.0254m
12 inches make 1 foot = 0.3048m
3 feet make 1 yard = 0.9144m
22 yards make 1 chain = 20.12m
10 chains make 1 furlong = 201.2m
8 furlongs make 1 mile 1.609 km


https://youtu.be/cmb1LbI6BgU

Class activity
Mention industries/workshops/persons that carryout some measurements
Identify and write down the units of measurements they use
Classify these units under S.I units and other units

Example 1
Convert 3550km to miles (b) The length of an iron rod is given as 66 inches. What is its length in metres?

Solution
1 mile = 1.609km
Hence, 3550km = (3550 x 1.609) miles
= 5,712 miles

(b). 1 inch = 2.54cm
Therefore 66 inches = (66 x 2.54) cm = 167.64cm.
But 100cm = 1m,
Thus 167.64cm = (167.64 / 100)m = 1.6764m

Therefore the length of the iron rod in metres is 1.676.4m

Evaluation
The height of a girl is 7.5 feet. Estimate her height in metres
Convert 30km to miles


Measurement of volume
Volume is a measure of the space contained in an object. For a regular solid such as a rectangular tank, its volume is given as length x breadth x height which can be in m3, cm3 mm3 e.t.c. Nigeria is an oil producing nation and a member of ‘OPEC ‘ that export oil to other nations. The volume of oil is measured in barrels. What then is a barrel? It is a unit of measurement of volume in the industrial sector. A barrel of oil is equivalent to 158.987 litres.
Example 2
The table below is a statistics of oil exportation to the United States for three years by NNPC
Year Price per barrel ( N ) Volume exported (barrels)
1993 140 1.05 million
1994 135 1.5 million
1995 162 0.9 million



1. What volume of oil in litres was exported in 1994?
2. What is the highest amount gotten and in what year was it gotten?

Solution
In 1994, 1.5 million barrels of oil was exported.
Since 1 barrel = 158.987 litres
1.05 million barrels = (1.5million x 158.987) litres = 238.4805million litres
(b) In 1993, volume of oil exported = 1.05 million barrels. Price per barrel = N140
Amount realized = 1.05million x 140 = N147,000000
In 1994, volume of oil exported = 1.5million, price per barrel = N135
Amount realized = 1.5million x N135 = N202.5 million
In 1995, volume of oil exported = 0.9 million barrels. Price per barrel = N162
Amount realized = 0.9 million x N162 = N145.8 million
Therefore, the highest amount of money gotten is N202.5 million and it was gotten in 1994



Measurement of temperature/power
We have learnt earlier that temperature is the degree of hotness or coldness of a body. And the instrument for measuring it is the thermometer. The S.I unit of temperature is Kelvin. In Britain and some countries and industrial sectors, the degree Fahrenheit is still in use. The difference between the Celsius scale and the Fahrenheit scales of measuring temperature is that the Celsius scale has 0 degree as its lower fixed point ( the melting point of pure water ) and 100 degrees as its upper fixed point ( the boiling point of pure water at standard atmospheric pressure). There are 100 divisions in between these points. The Fahrenheit scale has 32 degrees as its lower fixed point ( the melting point of pure water) and 212 degrees Fahrenheit as its upper fixed point.

The Celsius Scale is related to the Fahrenheit scale by the equation:

F is temperature in Fahrenheit scale, C is temperature in Celsius scale

F- 32/180=C/100 or C/5= F-32/9

Example
(a) Convert 77 degrees Fahrenheit to Celsius scale (b) Convert 105 degrees Celsius to degrees Fahrenheit
Solution
(a). Considering the equation



Measurement of power
Power is the time rate at which work is done. Its S.I unit is watt. The horse power is a common unit of power used in the industrial sector. The power of some machines, e.g air conditioners, water pump, cassava grinding machine e.tc are usually expressed in horse power. One horse power is equal to 746watts.
Example
A machine is rated 2500watts. Calculate the power in horse power

Solution
1 horse power = 746watts

Therefore 2500watts = (2500 / 746) horse power = 3.35 horse power

Assignment
Reading assignment: Read on electrical continuity testing
Convert 850 barrels to m3
Convert 52 inches to cm
Convert 987 feet to m

https://www.youtube.com/watch?v=oAtDAoq ... qdExw&t=12

TOPIC: SURFACE TENSION
CONTENT: * Definition of surface tension
* Effect of surface tension
* Application of surface tension
* Reduction of surface tension

Surface Tension:
(1) Is the property of a liquid to make its surface behave as though it is covered by an elastic skin.
(2) Is the force per unit length? Y= F/2L
(3) Is the force acting parallel to the surface of the liquid?
https://youtu.be/6YGLfZG5lEQ

https://youtu.be/zMzqiAuOSz0

Effects of Surface Tension
1 Soap bubbles are spherical in shape
2. Water skaters are able to walk on the surface of water
3. Razor blade or needle gently placed on the surface of water floats
4. Spilled mercury on glass surface form spherical droplets
https://youtu.be/khId_1SGj4U

Application of surface tension
(1) use in the manufacturing of rain proof or water proof
(2) absorption of ink with blotting paper
(3) rising of oil in lamp wicks
(4) movement of melted wax into the neck of a burning candle

Reduction of surface tension
(1) adding impurities such as detergent/soap, alcohol, oil, camphor, kerosene, grease
(2) by heating the liquid.

EVALUATION
1. Define surface tension
2. State the three effects of surface tension
3. State three applications of surface tension
4. State two ways of reducing surface tension

Reading Assignment : Read more on surface tension – New school physics (pg102-103)

General Evaluation:
1. A platinum-resistance thermometer has a resistance of 5Ω at 00C and 9Ω at 1000C. Assuming that resistance changes uniformly with temperature. Calculate the resistance of the thermometer when the temperature is 450C
2. Give two reasons why water is considered an unsuitable liquid for thermometers.

ASSIGNMENT
1. Define surface tension. State the three effects of surface tension
2. (a)State three applications of surface tension (b)two ways of reducing surface tension



TOPIC: CAPILIARITY
CONTENT: Definition of Capillarity
Cohesion and adhesion
Application of capillarity


Capillarity is defined as the tendency of liquids to rise or fall in narrow capillary tubes.

Cohesive force is the force of attraction between molecules of the same substance

Adhesive force is the force of attraction between molecules of different substance or it refers to the force which makes molecules of different substance to attract.

Application of Capillarity
Adhesion of water to glass is stronger than the cohesion of water, hence, when water is spilled on a clean glass surface, it wets the glass. The cohesion of mercury is greater than its adhesion to glass, hence, mercury spilled 0n glass forms small spherical droplets.
https://youtu.be/h41NgpuTLZ8

EVALUATION
1. Differentiate between cohesion and adhesion
2. Explain the rise of water in a glass capillary tube using kinetic theory
Reading Assignment : Read more on capillarity – New school physics (pg104-105)


General Revision
1. A metal rod of length 40.0cm at 200C is heated to a temperature of 450C. If the new length of the rod is 40.05cm, calculate its linear expansivity.
2. State two(02) disadvantages of thermal expansion of solids.

ASSIGNMENT
1. The blade of a wooden hoe feels cold to the touch in the morning than the wooden handle because the (a) blade is a better conductor of heat than the handle (b) handle is a better conductor of heat than the blade (c) blade is placed at a lower temperature than handle (d) handle contains store energy in the form of heat
2. Which of the following statement is not correct? (a) a sea breeze is due to convection in air (b) cotton material are better than woollen ones for use in the same weather (c) convection current plays an important role in the cooling of the engine of car (d)
the vacuum space in the flask helps to reduce heat loss by radiation.
3. The inside of a vacuum flask is always coated with silver to reduce heat loss by (a) convection (b) conduction (c) radiation (d) evaporation
4. Which of the following colours of surface will radiate heat energy best? (a) red (b) white (c) black (d) yellow
5. A hot metal in a vacuum can lose heat by (a) conduction (b) convection (c) radiation (d) conduction and convection
Theory
1 Differentiate between cohesion and adhesion
2.Explain the rise of water in a glass capillary tube using kinetic theory






TOPIC: Electric field
CONTENT: 1. Electric current, potential difference, Electromotive force
2. Resistance, types and calculations

Electric current, potential difference, Electromotive force

Electric current (l): is defined as the rate of flow of electric charge along a conductor.

I=Q/t

Q is the quantity of charge measured in Coulomb, ‘t’ is the time in second . I is the current in Ampere(A).There are submultiples of Ampere

1mA = 10-3A

1μA = 10-6A



https://youtu.be/XWlZ9bfGIoI

Electric circuit
An electric circuit is the path provided for the flow of electric current.
An electric circuit is a system that consists of the source of electricity, the key or switch and the connecting wires, ammeter to measure the current, voltmeter to measure the potential difference, Resistor or load and a rheostat to adjust the flow of current.


https://youtu.be/shJAV59NS6k

CIRCUIT DIAGRAM



Closed Circuit: It is a circuit in which there is no gap (key closed) along the conducting path.


Open circuit: It is a circuit in which there is a gap (key open) along the conducting path.


Short Circuit: A short circuit is a closed circuit without a load. The terminals of the cell are connected together.


Potential difference ( V): The potential difference between any two points in an electric field is defined as the work done in moving a positive charge of 1 coulomb from one point in the electric field to another. Potential difference is measured in volts.
Voltmeter is used to measure potential difference.


V = work/charge

Electromotive force: Electromotive force is defined as the total work done in driving one coulomb of electricity round a circuit or the total energy per coulomb obtained from a cell or battery.

E.m.f = work/charge

Resistance: This can be defined as the opposition to the flow of charges (electrons) or current. Its unit is Ohm. It is measured using Ohmmeter.

Types of Resistors:
i. Fixed/standard resistor: They have fixed resistance. The electrical symbol is

OR
ii. Variable resistor: They are those resistors whose resistance can be varied such as Resistance box and Rheostat. The electrical symbols are



https://youtu.be/9urCoY9aBnM

EVALUATION:
1. Define the following terms i. lines of force ii. Potential difference iii. Resistor iv. Electromotive force v. current.




SOURCES OF ELECTRIC CURRENT

Electric current can be generated from the following sources.
1. Chemical energy: Electrical cells store chemical energy. There are two types of electrical cell. The primary cell and the secondary cell. The primary cell cannot be recharged while the secondary cell can be recharged.
2. Heat Energy: Electricity can be generated by thermoelectric effect using a thermocouple, which consists of two different metallic wires joined and dipped in hot water while the other end is connected to a sensitive galvanometer.
3. Mechanical Energy: Current can be obtained from the generator. The generator converts mechanical energy to electrical energy by the principle of electromagnetic induction.
4. Solar Energy: Electricity can be generated from solar energy using the solar cell. In the solar cell solar energy is converted to electrical energy.
https://youtu.be/IRBpg94DzC8
https://youtu.be/15MY7abeCDk

GENERAL EVALUATION
Explain at least three sources of generating electricity.

WEEKEND ASSIGNMENT
1. Which of the following is not part of circuit?
A. cell B. Key C. load D. film
2. Which of the following is stored by a dry leclanche cell ?
A. Chemical energy B. Nuclear energy
C. Solar energy D. Heat energy.
3. Electrical resistance is the property of a conductor that enables electrical to be converted to
A. heat energy B. chemical energy C. mechanical energy D. solar energy
4. Which of the following statements is not correct about an electric field?
A. It is a force field. B. It is a scalar quantity
C. Its strength may be expressed in volts per meter.
D. Its intensity at a point obeys the inverse square law.
5. In a domestic circuit, electrical appliances and lamps are arranged in parallel across the
mains so as to enable the
A. same current to flow through the electrical appliances and the lamps.
B. maximum energy to be consumed at least cost.
C. same fuse to be used for the electrical appliances and the lamps.
D. voltage across the appliances not to be affected when the lamps are switched on and
off.

1. (a) Define electric field.
(b) Draw the electric field pattern around two unlike charges.
2. (a) Define the electromotive force and terminal potential difference of a battery.
(b) Explain why the electromotive force of a cell is not always the same as the
potential difference between its terminals.

PRE-READING ASSIGNMENT
Read Ohm’s law in your physics Text book

ACTIVITY: State Ohm’s law.

TOPIC: ELECTRIC FIELD

CONTENT: 1. Arrangement of resistors and Ohm’s law
2. Calculations using Ohm’s law
3 Electrical energy and power
3. Continuity faults in electric circuit, Fuse and circuit breaker.

Arrangement of resistors and Ohm’s law

Resistors can be arranged in series and in parallel

When resistors are arranged in series in a circuit, the same current flows but, they have different potential differences. When they are connected in parallel, they have the same potential difference but different current.
https://youtu.be/pd3RkGs1Tsg



OHM’S LAW
The electric current passing through a metallic conductor at constant temperature is directly proportional to the potential difference applied between its end.
https://youtu.be/NfcgA1axPLo

Current = Potential difference/Resistance

V = IR

R is a constant of proportionality and depends on the nature of the material. The unit of resistance is ohm.

CALCULATIONS
1. A potential difference of 240V is applied to a lamp of 60 ohms resistance. What amount of current
will flow in the circuit?

SOLUTION

Current = Potential difference/Resistance

I=240/60=4A


2. Calculate the effective resistance in the diagram
shown below.


SOLUTION:
Solve the parallel first,



3. A current of 3A flows in a circuit when a p.d of 24V is applied to it. The resistance across the circuit is

a. Calculate the total resistance in the circuit above
b. Calculate the current flowing in the circuit above

From question 2, Total resistance = 5Ω.
From Ohm’s law,

Current = Potential difference/Resistance

I=20/5=4A

https://youtu.be/NtMoOhRTuH0

EVALUATION
1. A cell of e.m.f 1.5V and internal resistance of 2.5W is connected in series with an ammeter of
resistance 0.5W and a resistor of resistance 7.0W. Calculate current in the circuit.
A. 0.15A B. 0.20A C. 0.60A D. 3.00A
2. Calculate the terminal potential difference across a 20W resistor connected to a battery of e.m.f
15V and internal resistance 5W.
A. 60.0V B. 15.0 C. 12.0V D. 6.3V




Electrical energy and power

Electrical Energy: If Q coulombs of electricity flows between two points whose potential difference is V volts, then the work done (W) is given by

W = QV

JOULES = COULOMB X VOLTS

But Q = It

Then W = VIt, E = VIt OR I²Rt OR V²/R

Electrical Power (P): Power is defined as the rate of doing work.

Power=Energy/time

Power=VIt/t

Power = VI = I²R = V²/R

https://youtu.be/41-37Kv_ljw

ELECTRIC METER READING AND BILLING
To measure or read electricity consumed in order to bill the consumer accordingly, the standard unit commonly used is the kilowatt/hour.
1 unit of the electric power is the watt
1 watt= 1 volts x 1 ampere
Hence, the electrical meter is a device used for recording the number of units of electrical energy consumed in a house over a period of time.

1KWh = 1000 x 60 x60J

= 3.6 X 106 Joules of energy

The actual cost per unit to electrical energy varies with the nature of the use to which the energy is put.
The PHCN also charges a fixed charge and meter maintenance charge every month. This also varies according to the tariff rate of the consumer.

Example: 1. the tariff rate of a consumer is N4. 00 per unit. The present meter reading is 3760 while the reading was 3648.
What is the consumption of the household after one month?
If the fixed charge is N30 and the meter maintenance charge is N100. What is the current charge of the consumer?

SOLUTION: i. the consumption of the household is the difference between the present reading and the previous reading.

– 3648 = 112units.

ii. The energy charge of the consumer = 112 x 4. 00 = N448. 00k
Fixed charges = N30
Meter maintenance charge = N100
Current charges =N(448 + 30 + 100) = N578 . 00

https://youtu.be/3G9I1unyOqY

EVALUATION
1. A1600 Watts electric oven is used for 9 hours. Calculate the cost of using the N3. 00 per unit of energy. (Energy Consumed = power x time).What are the functions of the ammeter and voltmeter?


Fuse and circuit breaker, Continuity faults in electric circuit.

FUSE AND CIRCUIT BREAKER
Fuse is a safety device containing a short length of thin conducting wire, which melts and breaks the circuit, if the current exceeds a certain safe value or maximum operating limit.

Circuit Breaker on the other hand works in the same way as the fuse. It is usually placed beside the electric meter such that the current enters it first before going into the meter.

Continuity Tester: To detect faults in a circuit, we use a continuity tester. It is used to test whether a circuit is continuous or broken at a certain point.


https://youtu.be/TNjBKTijmPw

GENERAL EVALUATION
1. A car fuse is marked 15A and operates normally on a 12V battery. Calculate the resistance of the fuse wire.

ASSIGNMENT
1. Calculate the terminal potential difference across a 20W resistor connected to a battery of e.m.f 15V and internal resistance 5W.
A. 60.0V B. 15.0V C. 12.0V D. 6.3V

2. Two identical cells each of emf 2V and internal resistance 1.0W are connected in parallel. The
combination is connected to an external load of 1.5W. Calculate the current in the circuit.
A. 0.57A B. 1.00A C. 1.14A D. 2.00A

3. A car fuse marked 3A operates optimally on a 12V battery, calculate the resistance of the fuse.
A. 36.0W B. 15.0W C. 9.0W D. 4.0W
4. A lamp is marked 220V, 60W. Calculate the energy it would consume when connected to a
220V source for 1 hour.
A. 216000J B. 13200J C. 3600J C. 864J

5. Three identical lamps each of power 100W, are connected in parallel across a potential
difference of 250V. Calculate the current in the circuit.
A. 7.5A B. 2.5A C. 1.2A D. 0.8A

ESSAY
1. A television 65W, a refrigerator 12kW, an electric kettle 650W and 10 lamps 40W each are connected in series in a house. How much will it cost the housekeeper to switch on all the appliances for 24 hours, if the cost of electricity is 15 kobo per KWh?
2. An electric heater is rated 1000W, 250V.
a. Calculate the resistance of the heating element when in use.
b. If electricity is charged at N2 per kilowatt hour and the heater is used for 30min each day, calculate the cost per month for 30days.

PRE-READING ASSIGNMENT
Read about solar collector in your Text book.

ACTIVITY
State the uses of solar energy.

REFERENCE TEXTS:
1. New School Physics for senior secondary schools by M.W. Anyakoha
2. Senior secondary physics by P.N Okeke, F.N Okeke, S.F. Akande

TOPIC: ELASTICITY
CONTENT : Definition of elasticity
Hook’s law
Tensile stress, tensile strain and young modulus

Elasticity is the tendency of a material to regain its original size or shape after deformation or after it has been compressed or extended.

Hook’s law states that provided the elastic limit is not exceeded, the extension in an elastic material (wire) is proportional to the force applied i.e Fαe
F = Ke…………………………………………1
Where K is force constant, stiffness or elastic constant
Force constant is the amount of force that causes a unit extension. It is the ratio of force to extension of an elastic material.
K → force constant, stiffness or elastic constant




OE →proportional limit
E→ elastic limit
Y→ yield point
EY → elastic deform
YM→ plastic deform
Hook’s law applies up to the elastic limit. For load beyond L the wire (material) stretch permanently. The point where small ↑ in load produces large extension is known as yield point.

Breaking point is the point where the wire cannot withstand any further increase in load.

Yield point : it is the minimum stress/load acting on an elastic material beyond which plastic deformation sets in.

Elastic limit is the maximum load (force) which a body can experience and still regain its original size.

Tensile stress is the force acting on a unit CSA of a wire/rod or force per unit CSA of a wire or rod.
Tensile stress = Force/Area …………………….2

Tensile strain is the extension per unit length
Tensile strain = extension/Original length ……………………..3

Young modulus can be defined as the ratio of tensile stress to tensile strain
Young modules = tensile stress/ tensile strain…………………..4
https://youtu.be/FAHOI32oAns
https://youtu.be/9QVmX3iGYAw

EVALUATION
1. Define (a) elastic limit (b) elastic constant (c) yield point (d) breaking point
2. State Hooke;s law of elasticity
3.Define young modulus of elasticity
4. A spiral spring extends from a length of 10.01cm to 10.10cm when a force of 20N is applied on it.Calculate the force constant of the spring

Reading Assignment : Read more on elasticity – New school physics (pg 93-96)

General Evaluation:
1. explain the anomalous behaviour of water.
2. State three ways of producing static electric charges

ASSIGNMENT
1.The SI unit of tensile stress is ….. (a) N/m (b) Nm (c) N/m2 (d) m2
2.The SI unit of tensile strain is ….. (a) N/m (b) Nm (c) N/m2 (d) none of the above
3. Young modulus of elasticity is the atio of tensile stress to tensile strain provide the load does not exceed the (a) breaking point (b) elastic limit (c) yield point (d) stress limit
4. A piece of rubber 10cm long stretches 6mm when a load of 100N is hung from it. What is the strain? (a)60 (b)0.6 (c) 6x10-2 (d) 6x10-3
5. Hooke’s law states that (a) F α A (b)F α e (c) E α F (d) E α A
THEORY
1. A wire is gradually stretched by loading it until it snaps (a) sketch a load- extension graph for the wire
2. indicate on the graph the elastic limit(E), yield point (Y) and breaking point (B)




TOPIC : ENERGY STORED IN AN ELASTIC MATERIAL
CONTENT : Force in a bar
Energy stored in a wire
Energy stored per unit area
Force in a bar
When a bar is heated and then prevented from contracting as it cools, a considerable force is exerted at the end of the bar. Given a bar of a young modulus E, a cross sectional area A, a linear expansivity of magnitude α and a decrease in temperature of Ө,then
E = stress/strain = F/A/e/L
=F/A х L/e
E = FL/Ae
F = EAe/L ………………………….1
Recall, Linear expansivity α = change in length/original length х temperature change
α = e/L х Ө
e = αLӨ
F = EAαeLӨ/eL
F = EAαӨ ……………………………2

EVALUATION
1. Show that F = EAαӨ when a bar is heated and then prevented from contracting as it cools
2. A steel rod of cross sectional area 2cm2 is heated to 100˚C and then prevented from contracting when it cooled to 10˚C. find the force exerted on the steel = 12 х 10-6/K and young modulus is 2 х1011N/m2



ENERGY STORED IN A WIRE
The application of force on any wire provided the elasticity limit is not exceeded is proportional to the extension provided.
Consequently, the force in the wire has increase from zero to F
Average force = F + O/2 = F/2
Recall work done = Average force х distance
W = f/2 x e = ½ Fe ………………………….3
Substitute eqn 1 into 3
W = EAe2/2L……………………………….4

ENERGY STORED PER UNIT VOLUME
WV = ½ X Stress X Strain…………………..5
This implies that Wv = Ee2/2L2

Substance which lengthens considerable and undergo plastic deformation until they break are known as ductile substance. E.g lead, copper, wrought iron.
Substance which break after the elastic limit is reached are known as brittle substance e.g glass and high carbon steel. It should be noted that brass, bronze and many alloys appears to have no yield point. By this we mean that this material increase in length beyond the elastic limit as the lead is increased without the sudden appearance of a plastic stage.

EVALUATION
1. A uniform steel wire of length 4m and are of cross section 3x10-6m2 is extended by 1mm. Calculate the energy stored in the wire if the elastic limit is not exceeded (young modulus = 2x1011n/m2)
2. A spiral spring is compressed by 0.02m. Calculate the energy stored in the spring if the force constant is 400n/m2
Reading Assignment : Read more on elasticity – New school physics (pg96-98)

General Evaluation
1. A body moving with uniform acceleration has two points [5,15 and 20,60] on the velocity time graph of its motion. Calculate its acceleration.
2. A body of mass 50Kg is moving in a circular path of radius 4m with a uniform speed 20m/s. determine its centripetal force
WEEKEND ASSIGNMENT
1. Young modulus of elasticity is the ratio of tensile stress to tensile strain provide the load does not exceed the (a) breaking point (b) elastic limit (c) yield point (d) stress limit
2. A piece of rubber 10cm long stretches 6mm when a load of 100N is hung from it. What is the strain? (a)60 (b)0.6 (c) 6x10-2 (d) 6x10-3
3. A force of 1.8N extends a wire by 0.4cm. what force will extend the wire by 1.25cm if the elastic limit is not exceeded . (a) 5.625N (b)4.500N (c) 3.125N (d) 2.25N
4. Calculate the work done to stretch a string by 40cm if a force of 10N produces an extension of 4cm in it. (a) 0.2J (b)2.0J ( C)20.0J (d) 200.0J
5. Which of the following is not the consequence of a force field ? (a) weight (b) surface tension (c) gravitational pull (d) magnetic force
THEORY
1. A steel rod of cross sectional area 2cm2 is heated to 100˚C and then prevented from contracting when it cooled to 10˚C. find the force exerted on the steel = 12 х 10-6/K and young modulus is 2 х1011N/m2
2. A uniform steel wire of length 4m and are of cross section 3x10-6m2 is extended by 1mm. Calculate the energy stored in the wire if the elastic limit is not exceeded (young modulus = 2x1011n/m2




TOPIC: SOLAR COLLECTOR

CONTENT: 1. Role of the sun in energy production
2. Solar cell
3 Solar collector
3. Construction of a solar panel .


Role of the sun in energy production.
The sun is a spherical central body of the solar system that radiates light and heat. It has a diameter of 1,384,000km and lies at an average distance of 148,800,000 km from the earth. It is liquid internally and gaseous outwards. The sun produces an enormous output of energy through nuclear fusion. The temperature of the sun is estimated to be about 6000k.
https://youtu.be/hL2PbAy99wE

Importance of solar energy:
1. Plants need energy from the sun for photosynthesis’
2. Direct heating warms our body, early morning sun is a source of vitamin D.
3. It can be used to dry our cloth, food items, preservation of food.
4. It can be used to generate electricity as in solar panel.
5. It can be used to heat water as in solar water heater.
6. it can be used for cooking as in solar furnace
https://youtu.be/GA81QgPlB1U

Solar Cell:
This is a device used for the purpose of producing electric power. It consists of semi-conductor like silicon, copper, copper (1) oxide. It converts solar energy to electricity by the use of photo voltaic effect.


Solar panel: The essence of solar panel is to trap sunlight to generate electricity. It consists of millions of solar cells joined together to generate electricity of high voltage.


EVALUATION:
1. State at least five uses of solar energy?
2. Mention materials used in the construction of a solar panel and state the reasons why those materials are being used.