JSS2 BASIC TECHNOLOGY

10/09/2020 ANSWER TO OBJECTIVES QUESTION

  1. B
  2. D
  3. C
  4. B
  5. D
  6. D
  7. A
  8. B
  9. B
  10. D

DATE: 01/09/2020

TOPIC: General View

  1. The line that passes through the center and touches the circumference of the circle is known as   ————-A. Arc  B. Chord  C. Diameter  D. Tangent
  2. The following are parts of a circle EXCEPT ————A. Chord  B. Diameter  C. Section  D. Segment
  3. An area bounded by an arc and two radii is known as ———–A. Sector  B. Chord  C. Tangent  D. Quadrant
  4. Any angle that is more than 90 but less than 180 is called ———– angle A. Acute   B. Obtuse   C. Right  D. Supplementary
  5. The addition of two angles to form 180 is called ————- angle A.Complimentary  B. Obtuse  C. Acute  D. Supplementary
  6. All the following angles can be constructed using only a pair of compasses and ruler EXCEPT ——A. 75  b. 72  C. 90  D. 45
  7. The triangle that has unequal sides is called ————- triangle A. Equilateral   B. Scalene   C. Isosceles   D. Right angle
  8. Heptagon is bounded by ————- lines. A. 10  B. 9  C. 8  D. 7
  9. A perpendicular line is always at—————to the hozontal . A. 360O  B. 180O  C. 900   D. 60O   E. 30O
  10. Continuous thick line is used for————A. Centre line       B. Cutting plane   C. Leader    D. Out line    E. Projector

ANSWER TO THE OBJECTIVES QUESTION

  1. A
  2. C
  3. C
  4. C
  5. A
  6. B
  7. A
  8. B
  9. B
  10. NO ANSWER every of the options are correct uses of wood

25/08/2020

Topic: General View

TOPIC: General View               

  1. Which of the following metals is used for making the body of an aeroplane? ____________a) Aluminium  b) Copper  c) Lead  d) Steel
  2. Block engine is made from______________a) Aluminium  b) Brass  c) Cast iron  d) Steel
  3. Catapult is a weapon made from____________ material a)Metal  b) Plastic  c) Rubber  d) Glass
  4. Spark plug is a product used in motor car engine, it is made from____________a) Glass  b) Wood  c) Ceramic  d) Plastic
  5. Rain coat is a _____________ product a) Rubber  b) Fibre  c) Wool  d) Fabric
  6. The medal given to third position in sport is a ____________ product a) Aluminium  b) Bronze  c) Cast iron  d) Lead
  7. Orthopaedic limbs used to replace broken limbs is mostly made of ___________ material a) Plastic  b) Metal  c) Metal  d) Wood Tyres and tubes have __________ property a) Plasticity  b) Elasticity  c) Ductility  d) Malleability n Wood is used for the following in building construction EXCEPT ____________a) Foundation  b) Roof  c) Window  d) wall
  8. The following are uses of wood EXCEPT____________
  9. Pulps  b) Tool handles  c) Transportation  d) Medicine

CALCULATION ON GEAR RATIO AND SPEED RATIO

  1. Calculate the gear ratio of a driving gear with 15 teeth and the driven gear teeth with 60 teeth
  2. If the speed of a driving gear is 90 rev/min and the driven gear is 60 rev/min. calculate the speed ratio.
  3. If the gear ratio is 100 and the driver gear has 40 teeth , what will be the driven gear teeth?
  4. If the speed ratio of a driving gear with 60 rev/min is 200. What will be the revolution per minutes of the driven gear.

Date: 18/08/2020

Topic: Gears (Continue)

Lubricants

Lubricants are oily substances or materials that are applied on metal surfaces or parts to make the surfaces or parts slippery and to work smoothly without noise and damages. Lubricants contain ninety percent base oil and less than ten percent additives such as esters, silicones, fluorocarbons, etc.

The different types of lubricants used in gear and machines are:

  1. Oils: These are liquid lubricants used in all engines, hydraulics used in brakes, etc.
  2. Greases: These are semi-solid lubricants containing thicken agent. They are used to prevent rust, friction, etc in machines parts.
  3. Gases: Nitrogen, Helium, etc are examples of air lubricants.
  4. Dry lubricants: These are solid, bulky or paint-like lubricants used in solid form.

Functions of Lubricant

  1. Prevent rust: Lubricants ( oil, grease, coolant, etc) prevent corrosion of gear parts. Absence of oil on metal causes the metal to turn brownish when in contact with water.
  2. Prevent wear and tear: Oily substances in gears prevent the wear and tear of gear teeth. Gear teeth mesh properly and slide easily.
  3. Reduce heat: Lubricants reduce heat from gears resulting from friction. Lubricants serve as an agent that reduces and transports heat away from gear.
  4. Prevent gear seizure: Lubricants prevent premature failure or wearing out of the gear teeth. This helps to increase the service life, reduce cost of repair, etc of the gear.
  5. Transmit power: Lubricants assist to transmit power in automatic gear systems. Hydraulic fluid  is used for this purpose.

Factors to Consider When Choosing Lubricants for Gear

When selecting a lubricant for any gear usage or application, the Engineer should know the following factors:

  1. The type of material a gear is made from
  2. The operating conditions of the gear
  3. The operating temperature of the gear
  4. The load the  gear is used to perform
  5. The environmental conditions.

Properties/ Qualities of Good Lubricants

  1. High boiling point and low freezing point: It must have a high capacity to stay liquid within a wide range of the temperature.
  2. High viscosity: Viscosity is the sticky nature of lubricants. This shows the resistance or the nature of not flowing easily of a good lubricant.
  3. Non-corrosive: A good lubricant must not make metal parts or surfaces rust.
  4. Not easily evaporated: A good lubricant must not turn to  vapour easily when heated during friction.
  5. High chemical stability: A good lubricant must maintain its chemical proprety for a considerable long time or service life.

Method of Application of Lubricant

  1. Oil can method
  2. Oil splash method
  3. Oil pump method
  4. Oil gun method

    13/8/2020 GAER RATIO AND SPEED RATIO

Gear Ratio Gear ratio is the ratio of the number of teeth on the driver to that of the driven gears

                            G. R.  =  driver gear/driven gear

Speed Ratio  This is the  revolution or rotation per minutes of the driven gear to that driving gear

                            S.R     =   driven ratio/driver or driving ratio

                                         FUNCTION  OF GEAR

  1. Power  transmission
  2. Increased speed
  3. Change the direction of motion
  4. Select speed

        FUNCTIONS   OF  LUBRICANTS TO GEARS

The actions  of lubricants in gear system help the  gear to run smoothly and last longer. It prevents frictional force and reduces wear and tears of the gear.

LUBRICANTS are oily substances or materials that are applied on metal surfaces or parts of machines to make it run smoothly.

TYPES OF LUBRICANTS

  1. Oils
  2. Greases
  3. Gases [like nitrogen helium etc]air lubrication
  4. Dry lubricants

Functions of  lubricants

  1. Reduces friction
  2. Prevent rust
  3. Prevent wear and tears
  4. Reduce heat
  5. Prevent gear seizure
  6. Removal of wear

Transmit power

Date: 11/08/2020

Subject: Basic Technology

Topic: Gears

MEANING AND TYPES OF GEARS

Gear is a toothed wheel that is used to transmit power or motion between machine parts. Also, gears are wheels with uniform teeth cut around their edges. Gearing is the arrangement of gears in shafts for the purpose of motion transmission. When two gears engage or interlock, they are said to mesh. The gear that generates motion or power is called driver and the other gear is called the driven. When motion takes place between the driver and driven gear, they rotate in opposite direction to each other. If the driver rotates in clockwise direction, the driven rotates in anticlockwise direction. When it is desired for the driver and driven to rotate in the same direction, the third gear called Idler is introduced in between them.

TYPES OF GEARS

1. Spur gear: Spur gear is used to transmit drive between parallel shafts. This is the most common type of gear. It is economical, easy to maintain. It is slow speed gear and is used at almost any speed.

2. Bevel gear: Bevel gear is used to transmit motion between two perpendicular shafts. It is also used to change the direction of motion. Bevel gear is the intersecting coplanar shafts connected by gears.

3. Rack and Pinion: A rack is a toothed rod and the pinion is a round toothed gear. W hen the pinion turns, the rack moves in a straight line. It is used in automobile to convert the rotation of steering wheel into the left-to-right motion of the tie rods.

4. Sprockets: The sprocket is common in chain drives. It is used to run chains in bicycles, motorcycles, timing of engines, and conveyor systems.

          06/08/2020         EXAMPLES OF PNEUMATIC DEVICES

  1. Air brand the ake in buses, trucks, train etc
  2. Pneumatics  motors
  3. Pressure regulator
  4. Pipe organs
  5. Inflated materials such as balloons, tyres,  etc

                COMPONENTS OF PNEUMATIC DEVICES

  1. Fluid conductors
  2. The valves
  3. The actuators
  4. Pumping device
  5. Support components like filter, mufflers manifolds etc

                USES OF PNEUMATIC DEVICE

  1. Air brake
  2. Railway
  3. Compressed air engine
  4. Inflatable materials
  5. Pipe organs
  6. Air gun
  7. Dental drill
  8. Pneumatic tyres
  9. Pneumatic tools like jacks, impact entrench, air saw,etc
  10. Shock absorbers
  11. Vacuum cleaner

Date: 4/8/2020 Topic: Hydraulic and Pneumatic Machines Sub topic: Pneumatic Pneumatic refers to the use of compressed air to transmit force over a distance. The devices that operate with compressed air are called Pneumatic devices. Pneumatic Devices Pneumatics transmit power using a gas (air) instead of a liquid. Compressed air is usually used to transmit pressure with the exception of special gases for special applications. Pneumatic Devices are power system used to compress air as a working medium for power transmission. Pneumatic devices convert mechanical energy into pressure energy of compressed air. It works with pressurized gas to produce mechanical motion. Examples of Pneumatic Devices 1. Air brakes used in buses and trucks. 2. Pneumatic motor 3. Pipe organ used to produce sound 4. Inflated materials such as balloons, tyres, etc. Components of Pneumatic Devices 1. Fluid conductors: These are materials with round holes such as hoses, tubing, fittings, etc. that distribute pressurized gases through the system. They are non-corrosive, heat resistance, weather proof, etc. 2. The valve: These are parts that perform the functions of starting, stopping the flow of gas and direction of pressure fluid flow in the system. 3. The actuators: These are the cylinders, motors, rotary actuators, grippers, vacuum cups,etc. They perform pneumatic function of the machine. 4. Pumping device: This is the air compression device used to supply fluid power to the system. 5. Support components: These are filter that clean the air, pneumatic mufflers, manifolds, etc. They enable the system to function properly. Uses of Pneumatic devices 1. Air brakes: Air brakes are used to control the speed of trucks and buses. 2. Railway brakes: Air pressure is used to reduce train speed and bring it to a stop. 3. Dental drill: A dental drill uses pneumatic system, it is used by dentists to remove decay, shape tooth and cleaning and shaping of tooth. 4. Inflatable materials: Pneumatic is used to inflate materials such as balloons, tubes, tyres, etc.to store air 5. Shoch absorbers: Air balloons are used in trucks and heavy duty vehicles to provide damping and cushion to vehicles and trucks.

30/07/2020

HYDRAULIC  AND PNEUMATIC  DEVICES

Hydraulic devices   are devices that uses incompressible liquid to transmit pressure equally from one point to another. These devices consist of column of confined fluid with piston at each end. The fluid is called hydraulic fluid.

Example of hydraulic machines are:

  1. Bulldozers
  2. Pay loaders
  3. Cranes
  4. Airplane
  5. Elevator(lift)
  6. Hydraulic jack
  7. Automobile  brakes
  8. Automobile clutches
  9. Shock absorbers
  10. Barber chairs

THE COMPONENTS OF HYDRAULIC DEVICES

  1. A  reservoir : This is the storage tank for the hydraulic  fluid .
  2. The  pump : It helps to convert mechanical energy into hydraulic energy when the fluid move inside the reservoir.
  3. The valve: It directs the flow of the hydraulic fluid. 
  4. The actuator: It converts the hydraulic energy to mechanical energy.

HYDRAULIC  DEVICE PRINCIPLES

The  working  principles of hydraulic device works on the principle of Pascal law which states that, when pressure is applied in one part of the confined fluid, the pressure is transferred to all parts of the fluid. The smaller the piston, the smaller the energy transferred , the bigger the piston the bigger the energy transferred.

USES OF HYDRAULIC DEVICES

  1. It is used in car brakes.
  2. It is used in  airplane.
  3. It is used in heavy equipment.
  4. It is used in hydraulic jack.

30/07/2020

                         HYDRALIC AND  PNEUMATIC MACHINE

The use of air and fluid in technology cannot be over emphasis. Machine designer make use of Air  and Fluid in the manufacturing of machine 

Motion involves a change of position with time. In hydraulic and pneumatic machine we need to consider the speed and the pressure of the air flow

SPEED is the time rate at which a body cover a distance

            Speed=     Distance/ Time

The S. I  units of speed is m/s

PRESSURE is the amount of Force per specific area

             Pressure=   Force/Area

The S.I  Units of pressure is N/m2 or Pascal

 AIR FLOW  is the movement or motion of air from one place to another. This can be generated by

  1. Mouth
  2. Fan
  3. Air pump
  4. Bellow

The  Air flow depend on the speed and the pressure. The higher the pressure the higher the speed of the flow.

TYPES OF AIR FLOW   

1  Laminar Flow   This is a peaceful flow of air without any noise and disturbance

2  Turbulent  Flow  This is a flow of air at high speed which causes disturbance and damages

CLASS WORK

  1. Calculate the  Pressure required by a machine that  generate a force of 2000N within the area of 250m
  2. Calculate the  speed of air flow in a machine if the distance covered by the machine is 1250m per 25 seconds.  

DATE: 23-07-2020

Chain Drives

The arrangement and connection of continuous rolling chain with toothed sprockets which are in form of gears is known as chain drive. The connection is used to transmit motion between sprocket gears where slip is not allowed. Chain drive is a way of transmitting mechanical power from one place to another. It is used to move or convey power to the wheel of automobiles, bicycles, motorcycles, industrial and domestic machines, chain saws, etc.

Types of Chain

The various types of chain used for chain drives are:

1. Roll chain 2. Detachable chain 3. Leaf chain 4. Metal chain 5. Silent chain

Application of Chain Drive

1. Bicycle chain and sprocket: Bicycle uses chain meshed with the sprocket to drive. 2. Automobiles: Connection between the cam shaft and crank shaft of automobile engines uses chain drive. 3. Motorcycles: Chain and sprocket are used in motorcycles to transmit power from the engine to the wheel. 4. Fork lift: Fork lift is a machine used to lift and move heavy loads from high level to level or from one place to another. It uses chain drive to perform this task.

Advantages of Chain Drives

1. Chain drive is efficient because little friction exists between the chain and the sprocket gear. 2. It is reliable because it does not slip like belt drive. 3. It last longer than belt drive because it does not get worn out easily. 4. It saves cost and time for maintenance because it takes little lubrication for a longer period of time.

Disadvantages of Chain Drives

1. It can notbe used where long distance is required compared to belt drive and where driveshafts are separated by a large distance. 2. It can not be used to transmit power at inclined angle like crossed belt.

Uses of Belt Drives and Chain Drives

Belt and chain drives are used to: 1. Transmit power from driving shafts to the driven shaft when both shafts have longer distance between them than require for gears. 2. Change the direction of motion of a pulley. 3. Change speed of shafts either increase or reduce from the driving shaft. 4. Transport heavy materials from one location to another.

Comparison of Belt and Chain Drives With Gear Drives

1. Lubrication is required in gear and chain drives but belt drive does not need it. 2. Belt is cost effective when compared with chain and gear. 3. Belt and chain drives run or transmit motion in the same direction except crossed belt while gears transmit motion in opposite direction.

  21/07/2020                             BELT DRIVES AND CHIAN DRIVES

MOTION is crucial in machines. Machines are designed in other  to transmit motion from one location to the other. This can be achieved through either BELT DRIVES OR CHAIN DRIVES

There are 3 basics types of drives

  1. belt drives
  2. chain drives
  3. gear

BELT  DRIVES  This is the arrangement of belts and pulleys. They are used to transmits motion between two distance shafts. The belts moves round the groove of the pulley

BELTS are flexible materials used to transmit power by linking two or more rotating shafts.

TYPES OF BELTS

  1. Vee  belt
  2. Crossed belt
  3. Flat belt
  4. Chain belt
  5. Round belt
  6. Timing belt
  7. Film belt
  8. Toothed belt
  9. Ribbed belt

BELT can either be rubber, rope , leather , or strong fiber

      TYPES OF BELT DRIVES

  1. Open belt drive [is used to rotate the drive pulley system in the same direction]
  2. Cross belt drive [ is used to rotate driven pulley system  in the opposite direction]

APPLICATION OF BELT DRIVES

  1. Sewing machine
  2. Pepper grinding machine
  3. Automobile engine
  4. Cassette and Video tape player
  5. Refrigerator and Air –conditioner
  6. Timing engine
  7. Industrial usage[conveyors]

ADVANTAGES OF BELT DRIVES

  1. It require no lubrications
  2. It is convenient to fix
  3. It transmit motion over a long distance
  4. It is used to transmit power at an angle
  5. It Is cheaper compare to other drives
  6. It increase the life span of machine
  7. It has high efficiency

DISADVANTAGES  OF BELT DRIVES

  1. It losses energy due to friction
  2. It worn-out and break easily due to friction    

Date:16/07/2020

Topic: Belt and Chain Drive

FRICTION

Friction is a phenomenon that has relevance to motion especially belt and chain drive. Friction is defined as the resistance that one surface offers to its movement over another surface. The amount of friction depends upon the nature of two surfaces in contact. When two objects with flat surfaces are placed one on top of the other, if the two flat surfaces are smooth and they slide bt push or pull, there is free movement. But when the two surfaces are rough and they slide on one another, there will be no free movement. There would be a need for greater force for movement to occur between the two surfaces when they slide on each other. The reason for this is due to the roughness of their surfaces. This action is known as resistance to motion. The resistance to motion is called friction. For instance, to walk free without sliding, free occurs between the shoe and the ground.

Advantages of Friction

a. It makes the wheels (tyres) of an automobile grip the road to prevent slipping. b. It makes the brakes of moving cars, bicycles, trains, etc to slow down and stop when necessary. c. It allows conveyor belts to turn on pulleys without slipping off. d. It is difficult to walk on wet and smooth floor due to its slippery condition. Friction helps us to walk without slipping and falling.

Disadvantages of Friction

a. It produces heat which causes damage to machine parts. b. It causes wear and tear of moving parts. c. It causes dullness of cutting edges especially cutting tools like knife, chisel, etc. d. It reduces efficiency of machines.

14/07/2020

CONSTRUCTION OF A REGULAR PENTAGON GIVEN THE LENGTH OF ONE SIDE

STEPS TO FOLLOW

  1. Draw the given side AB and extend the line
  2. With centre A and radius AB draw a semi circle to a point C and divide it into 5 equal parts
  3. Draw a straight line from point A to point 2.This is the second side of the pentagon
  4. Bisect AB and A2.The bisecting lines intersect at O
  5. With centre O and radius OA draw a circle and mark the remaining 3 side of the pentagon on it
  6. Draw straight lines to join marked points to form the pentagon

    09/07/2020

                           POLYGON         

POLYGON is a plane figure bounded by more than four straight lines

        DIVISIONS  IN POLYGON

  1. Regular polygon
  2. Irregular polygon            

Regular  polygon :  are polygon with equal sides and  equal angles

Irregular polygon : are polygon with sides and angles not equal

        TYPES OF POLYGON

         1   PENTAGON   [5 SIDES]

         2   HEXAGON    [6 SIDES]

  • HEPTAGON   [7 SIDES]  
  • OCTAGON     [8 SIDES]
  • NONAGON   [9  SIDES]
  • DECAGON     [10  SIDES]

TO   CALCULATE THE EXTERIOR ANGLE OF A POLYGON

            Ext  angle  =  360o/N

Where N is the no of sides

CONSTRUCTION OF A TRAPEZIUM GIVEN THE TWO PARALLEL SIDES, ONE ANGLE ANDLAR PERPENDICU DISTANCE BETWEEN THE PARALLEL SIDES

STEPS TO FOLLOW

  1. Draw the given parallel side AB
  2. Construct the given angle ABG[600]
  3. Mark any point 1and2on line AB
  4. With 1 and 2 as centres and radius equal to the perpendicular distance between the two parallel sides draw an arc on the two point 1 and 2 above line AB
  5. Draw parallel line to line AB to cut line BGat C [note] BG is the construction line of angle 60o
  6. With centre C ,and radius  of the shorter parallel distance  draw an arc to mark point D
  7. Join point D to A to give the trapezium

DATE: 30/06/2020

TOPIC: GEOMETRIC DRAWING 2

Construction of Rectangle Given the Length of a Diagonal and One Side

  1. Draw the given diagonal AB.
  2. Bisect the diagonal AB and draw a circle on it.
  3. With centre A and radius of the given side draw an arc to cut the circle at C.
  4. With centre B and the same radius draw an arc to cut the circle at D.
  5. Join AC, CB, BD and DA to form the rectangle.

Construction of a Parallelogram Given the Length of the Two Sides and One Angle

  1. Draw the side AB.
  2. Construct the given angle ABE.
  3. With centre B a radius of the given other side, draw an arc to cut BE at C.
  4. With center A and radius BC draw an arc.
  5. With center C and a radius AB draw an arc to cut the previous one at D.
  6. Join AD and DC to form the parallelogram.

Construction of a Trapezium Given the Two Parallel Sides, One Angle and Perpendicular Distance Between the Parallel Sides.

  1. Draw the given angle side AB.
  2. Construct the given angle ABG (60).
  3. With 1 and 2 as centers and radius equal to the perpendicular distance between the parallel sides, mark arcs above and draw parallel line to cut line BG at C.
  4. With center C and shorter parallel side as radius mark point D.
  5. Join D to A to give the trapezium.

EXERCISES

  1. Construct a rectangle with diagonal 80mm and side 50mm.
  2. Construct a parallelogram with sides 40mm by 80mm and angle 105.

25/06/2020          JSS2

CONSTRUCTION OF A SQUARE GIVEN  THE LENGTH OF SIDE

STEPS TO FOLLOW

1 Draw the side AB

2 Construct RIGHT angle at point.

3. With centre A and radius AB draw an arc to cut the perpendicular at B.

4. With centre’s B and C and radius of side AB draw arcs to intersect at D.

                         CONSTRUCTION OF A RHOMBUS GIVEN THE LENGTH OF THE DIAGONAL AND SIDE

  1. Draw the diagonal AB.
  2. With centre A and B respectively and radius of side given, draw arcs above and below the line to intersect at C and D.
  3. Join AC, CD, BD and DA to inform the required rhombus.

GEOMETRIC  DRAWING 2 23/06/2020

QUADRILATERALS  is a plane figure bounded by four straight sides and angles

   TYPES OF QUADRILATERALS

 1 SQUARES: It has four equal sides and four right angles. The diagonals are equal, they bisect each other at angle 900

2  RHOMBUS:  Has four equal sides and its four angles are not right angle. Its diagonals bisect each other and angle 900

3. Rectangle: It has opposite sides equal and the four angle are right angle the diagonal and equal and bisect each other and angle 900

4. Parallelogram: Has the opposite sides equal but its four angle are not right angle the diagonal bisect each other but not equal

5. Trapezium: Its has two opposite sides parallel

6. Trapezoid or Deltoid or Kite: Its has pairs of adjacent sides equal.   

Construction of an inscribed to a given triangle

STEPS TO FOLLOW

  1. Draw the given triangle abc
  2. Bisect any 2 angles
  3. The bisecting lines intersect at a point o
  4. O is the centre of the circle
  5. Draw a perpendicular line from point o to linbe ab.
  6. The bisecting line meets line ab at d
  7. From centre o and radius od draw the inscribed circle

Construction of circumscribed to a given triangle

STEPS TO FOLLOW

  1. Draw the give triangle ABC
  2. Bisect any 2 sides of the triangle
  3. The bisecting line intersects at O
  4. Point o is the centre of the required circle
  5. At point o with radius OA draw the circle

note: the circle will pass through point ABC

Good morning students, hope you are keeping safe.

DATE: 16/6/2020

TOPIC: Revision on Geometric Drawing

Division of a circle into 8 equal parts

The following steps should be followed in dividing a circle into 8 equal parts:

  1.  Draw the given circle.
  2. Divide the circle into four equal parts
  3. Use 45 set-square with tee-square aid draw diagonal lines at opposite direction through the centre of the circle to meet the circumference.
  4. Thus the circle is divided into 8 equal parts.

Division of a Circle into 12 Equal Parts

Two methods can be used to divide a circle into 12 equal parts: compass method and 60/30 set square method.

Using the compass, the following steps should be followed:

  1. Draw the given circle and divide into four equal parts
  2. Expand your compass distance equal to the radius of the circle.
  3. At each of the four points A, B, C, and D make arcs to intersect the circumference of the circle.
  4. Thus the circle is divided into 12 equal parts.
  5. Join each of the parts 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11 to the centre of the circle.

Using the 30/60 set square, the following steps should be followed:

  1. Draw the given circle and divide into four equal parts.
  2. Use the 60 set square edge with tee square, draw a straight line through the centre to touch the circumference at both ends.
  3. Repeat the step ii using the 60 setsquare for the other quadrants.
  4. Turn to the edge of the 30 set square and draw a straight line through the centre to touch the circumference at both ends.

ACTIVITY

  1. Draw a circle of radius 60mm and divide it into 8 equal parts.
  2. Draw a circle of radius 60mm and divide it into 12 equal parts.

Date: 11|6|2020

REVISION ON GEOMETRIC DRAWING1

BISECTION OF ANGLES

Bisection of angles involves dividing a given angle into two equal parts. The following steps below should be followed in bisecting any angle:

i. Draw the given angle CAB

ii. Take your compass and place it at point ‘A’ to draw an arc touching lines ‘AC’ and ‘AB’ at point ‘D’ and ‘E’.

iii. At point ‘D’ and ‘E’ draw arcs at convenient radius to intersect each other at point ‘F’.

iv. Draw a line from point ‘A’ through point ‘F’.

v. The angle is divided into two equal parts.

CONSTRUCTION OF ANGLES

The methods of constructing the following angles: 90, 60, 45, 30,15, 120, 75, are discussed below:

CONSTRUCTION OF ANGLE 90

i. Draw line AB.

ii. With center ‘A’ any suitable radius draw an arc cutting AB at ‘C’.

iii. Using the same radius strike an arc from point ‘C’ cutting the first arc at point ‘D’.

iv. With center ‘D’ and the same radius strike another arc again to cut at point ‘E’.

v. Using any radius strike an arc from points ‘D’ and ‘E’ to intersect each other at ‘F’.

vi. Joint FA with a straight line.

vii. FAB= 90

CONSTRUCTION OF ANGLE 60

i. Draw a line AB.

ii. At point ‘A’ draw a big arc to touch AB at point ‘C’.

iii. With the same compass radius place your compass needle at point ‘C’.

iv. Draw an arc to intersect the big arc at point ‘D’.

v. Draw a line from point ‘A’ through point ‘D’.

v. Therefore EAB= 60.

CONSTRUCTION OF ANGLE 45

i. Construct angle 90

ii. Bisect angle 90 EAB by drawing arcs from point ‘F’ and ‘C’ to intersect at point ‘G’.

iii. Draw a straight line from ‘A’ passing through point ‘H’ to point ‘G’.

iv. Therefore GAB=45

CLASS ACTIVITY:

Construct the following angles:

a. Angle 45

b. Angle 60

c. Angle 90

9/06/2020

REVISION ON GEOMETRIC DRAWING 1:

BISECTION OF STRAIGHT LINES

Bisection means dividing into two equal parts. Therefore, bisection of a line means dividing a line into two equal parts. The following steps should be followed in bisecting a line:

i. Take your rule, measure and draw with a given line ‘AB’.

ii. Fix your pencil into the compass and extend to convenient radius more than half of the line ‘AB’.

iii. Place the needle point of the compass on point ‘A’ and draw arcs above and below the given line ‘AB’.

iv. Place the needle point of the compass on point ‘B’ and draw arcs to intersect the first two arcs.

v. Join the two intersection points with a straight vertical line to intersect the given horizontal line ‘AB’ at point ‘ C’.

DIVISION OF LINES

Division of a line means dividing a line into several equal parts as may be required. The following steps should be followed for division of a line:

i. Draw the given line AB using your tee square and pencil.

ii. Draw an inclined line AC at a convenient angle to AB using your ruler and pencil.

iii. Divide AC into the required equal parts using your divider or compass.

iv. Join the last division on AC to point ‘B’.

v. Then draw parallel line to B4 from each of the other points 1,2,3, to ‘AB’

CLASS ACTIVITY:

  1. Bisect a line 70mm.
  2. Divide a line 90mm into six equal parts.

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JSS 2

DATE: 4/6/2020

GEOMETRIC  DRAWING   1

TYPES  OF  LINES  AND  THEIR   USES.

Good morning students, hope you are doing fine.

LESSON FOUR

Date: 2/6/2020

Topic: Revision on Materials and Their Common Uses

The following are the different materials commonly used as raw materials in technology:

Wood

Metals

Ceramic and glass

Rubber

Plastic

Uses of Wood

1. Building construction: Houses have different parts which are made with wood. Such building parts are windows, doors, roofs, wardrobes, etc.

2. Furniture: Tables, chairs, cupboards, beds, and cabinets are made of wood. Those items are very useful in offices, schools, hospitals, etc.

3. Pulps: Paper used for making books, newspapers, toilet rolls, etc are products made from wood.

4. Tools handle: Poor conductivity of dried wood makes it very useful for tools handles such as hammers, planes, saw, chisels, axe, etc.

5. Transportation: Truck bodies, railway sleepers, canoes,, walking stick, boat paddles, etc are built with wood and man made boards.

6. Utensils: Wood has always been used for cutlery such as chopsticks, toothpicks, wooden spoons, etc.

7. Musical instruments: Wood is used for different musical instruments such as drums, guitars, piano, flutes, recorder, xylophone, etc.

Uses of Metals

Cast iron: This is useful for producing drain pipes, machine beds, car engine, piston rings, cylinder block, etc.

Wrought iron: It is used for shackles, chains, railings, gates, bolts and nuts, etc.

Mild steel: It is used for making tools and machines.

Stainless steel: It is used for engineering construction, hydraulic, etc.

Aluminium: It is used for cooking utensils, food containers, aircraft production, engine piston and cylinders.

Brass: It is used for iron mongeries like locks, door handles, door hinges and keys. It is also used for decoration, ammunition and electrical fittings.

Bronze: It is used for sports medals in third position. It is used for carving and ornament.

Zinc: It is used for roofing, galvanizing iron, coating metals against rust and making brass.

Duralumin:It is used for aircraft manufacture, tubes and sheets.

Uses of Ceramics and Glass

1. Building construction: Bricks, blocks, tiles, drain pipes, glazed doors and windows are ceramic and glass product. Other ceramic product used in building construction are pipes, sinks, water baths, water closets, roof tiles, etc.

Sculpture: Sculpture is the art of forming figure and ancient artifacts or statues. It can be fired and glazed for decoration and historical purposes.

Dinner wares: Ceramic wares make excellent containers for foods and drinks. Examples are glass, cups, mugs, tea cups, plates, dishes, etc. They are resistant to acids, salts and detergents. They do not absorb liquid and change in temperature.

Decoration: Decorative articles such as flower vases, photo frames, etc provide beautification to houses, offices, halls, churches, and event places.

Furnaces: Ovens or kiln used for firing clay products, baking breads, and cakes are made of bricks. This is possible because bricks are poor conductor of heat.

EXERCISES

1. List eight uses of wood.

2. List three uses of aluminum.

3. List six uses of ceramic

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Lesson three

Topic: Revision on First Aid

Meaning of First Aid

First aid is the emergency care or treatment given to an ill or injured person before regular medical aid can be obtained. It can also be defined as the first and immediate assistance given to any person suffering from either a minor or serious illness or injury, with care provided to preserve life, prevent the condition from worsening, or to promote recovery.

Importance of First Aid

1. First aid reduces hospital time: Early intervention with first aid can reduce the length of time the patient needs to stay in hospital.

2. First aid prevents medical situations deteriorating: Knowing the basics of first aid can prevent a bad situation from getting worse. Consider a patient who is bleeding from a deep cut. Without intervention, the patient could suffer a severe blood loss. By applying pressure using simple first aid techniques, you can prevent a medical emergency from rapidly deteriorating and stabilize the patient until further medical help arrives.

3. Crucial communication for the emergency services: Staying with the patient until the emergency services arrive to take over means you can convey vital information about how the patient sustained the injury or information about their condition. This information is vital to the emergency services for the effective treatment of the patient.

4. First aid saves lives: Basic first aid can mean the difference between life and death. A Red Cross survey showed a staggering 59% of deaths from injuries would have been preventable had first aid been given before the emergency services arrived.

First Aid Box and its Content

A first box is a kit containing various items used for first aid treatment.

The materials stored inside first box include hand gloves, analgesic, a pair of scissors, iodine, bandage, methylated spirit, balms e.t.c.

Questions

1. Who is a First Aider

2. State two reasons a First Aider should wear hand gloves before treating an accident victim with bleeding

3. Explaining two types of First Aid

4. State six importance of First Aid

Good day students,how are you doing ? By the special grace of God this holiday will be over and the normal and regular classroom teaching will start. Meanwhile,we’ll be using this medium for learning and teaching.

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BASIC TECHNOLOGY.

Date:18th of may,2020

Topic: Revision on Rescue Operation.

Meaning of Rescue Operation

Rescue Operation is an organized or planned life saving programme or activity put in place to bring people or persons out of danger, harm, attack, disaster, etc. Rescue is necessary when peoples lives are under treat or (danger) of death as a result of natural disaster such as flood, earthquake, or attack on human life like kidnapping or militant insurgency and other danger such as building collapse, site accident etc.

Rescue operation is carried out by trained personnel or volunteers in government organization and voluntary organizations. The various groups or organization that carry out rescue operation include:

  1. Police
  2. Fire Brigade
  3. Civil Defense Corps
  4. Federal Road Safety Commission (FRSC)
  5. National Emergency Management Agency (NEMA)
  6. Military
  7. Voluntary Association such as Red Cross, Boys Scout, Girls Guide, etc

Components of Rescue Operation

Rescue operation requires the following components:

  1. The rescuers: The are the trained personnel and volunteers who carry out rescue operation. Rescuers form the rescue team that makes decision and carry out operation immediately after receiving the distress calls or signals
  2. Tools: Availability of tools is very important to successful rescue operation. Tools to be used depend on the type and aspect of rescue to be done.
  3. Time: Time is an important factor to rescue victims. The first 24 hours after a disaster is known as “Golden Day”. This is the period or time during which victim have an 80 percent chance of survival if rescued.

Types of Rescue

The various type of rescue include:

  1. Combat Rescue
  2. Ground Search and Rescue
  3. Mountain Rescue
  4. Urban search and Rescue
  5. Air-sea Rescue
  6. Rope Rescue
  7. Dog search and Rescue

Rescue Operation Include:

  1. The handing of emergency call
  2. The issuing of warning to the public on impending danger, attack etc.
  3. The Combating of impending accidents.
  4. The protection of people, property and the environment against danger and rescue of accident victims.
  5. The extinguishing of fire and danger limitation during fire outbreak.
  6. Provision of medical care, support, relief such as provision of food, water clothing, housing, boots to victims.

Steps Involved in Rescue Operations

  1. Safety of rescuer: The important step to be considered in carrying out any rescue operation is to make sure that you do not put yourself at risk of hazard. Safety first is the slogan to be observed.
  2. Assessment of The Disaster: this is done by in-depth discussions and analysis of the incident or disaster. Take an in-depth study of the distress to decide what to do.
  3. Assessing Resources: Availability of personnel (rescuers), equipment and tools are very important to carry out rescue work. When resources are available rescue is possible as success is guaranteed.
  4. Evacuate injured person: Casualties must be transported out of the scene of the incident. Availability of ambulance to move victims to the hospital must be near.

Exercises

  1. Explain 4 aspect of Rescue Operation
  2. List 8 equipment to worn and used by rescuer during rescue operation
  3. State 6 steps involved in rescue operation and

Please write your name, e-mail and subject in the boxes provided below.

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LESSON TWO

DATE 20/05/2020

Topic; MATERIALS AND THEIR COMMON USES

USES OF WOOD

  1. Building construction
  2. Furniture
  3. Pulp
  4. Tools handles
  5. Transportation
  6. Plywood and boards
  7. Utensils
  8. Packaging
  9. Musical instruments
  10. Fuel(cooking)
  11. Engineering work

USES OF CERAMICS AND GLASS

  1. Sculpture
  2. Building construction
  3. Dinner wares
  4. Decorations
  5. Furnaces(ovens)
  6. Insulators

USES OF RUBBER

1 Insulator

2 Tyres and tubes

3 Mechanical products{gasket, hoses, belts, etc)

4 Waterproof{raincoats, rain boots,rubber mask,etc)

5 Medical purposes(hot water bottle,ice bag,syringes,gloves,etc}

6 Dampers[ shock absorbing,}

7 Elastic clothes

8 Rubber cement

9 Storage cases( tanks,bottles,battery case}

10 Cushions(pillows,rugs,mattresses etc}

Class Activity:

1 why is rubber used for syringes instead of plastic

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