tg_ tech_ gr 8_ 9

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LEARNINGAREA TECHNOLOGY

TECHNOLOGYGRADE

AND

TECHNOLOGYGRADE

TEACHERSGUIDE

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Phase synopsis (Grades 8 and 9)

DEFINITIONOF TECHNOLOGY

Technology is defined as:

The utilisation of knowledge, skills andresources to satisfy the needs and desires of peoplethrough the development of practical solutions toproblems, with consideration of social and environmentalfactors

This is not easily accomplished in theclassroom. OBE requires that we regard the learningprocess and the content as equally important.Technology is particularly suited to the OBE approach. It,

in fact, cannot be taught by any other means. Theprocess that the learners follow, rather than the content,forms the nucleus of the learning programme.

You therefore have to provide the learners with opportunities to solve problems byemploying their knowledge and skills. If learners do not have the necessary knowledgeor skills, they must acquire what they need by means of research or tasks. You, as theeducator, have the task of identifying the gaps in the learners abilities and guiding themthrough the enhancement of their capabilities by means of the learning programme.

The steps, or the Technological Process, are the guidelines for learners to follow the

correct procedure. The main steps of the process involve Investigating, Designing,Developing (making) and Evaluating. It is important for learners to assemble portfolios inthe course of the learning programme. The steps that the learner follows to solve theproblem must be presented in the portfolio. This provides the basis for evaluation,because it represents the learners own work. The following divisions must beidentifiable in the learners portfolio:

Research

Communication

Practical work

Knowledge of the technological process

Tests

It is most important that the learners portfolio be kept in a folder in the classroom. Eachmodule is provided with an assessment sheet for recording all the results obtained for aparticular module. You are advised to keep a copy of this assessment sheet in your ownfolder. Encourage learners to consult the assessment sheet regularly. The assessmentsheet will also help you to gain immediate access to the learners results in each of thelearning programmes, which will be particularly helpful during the process of moderation.This method also enables learners to obtain an overall view of the learning programme inthe particular phase.

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Synopsis of Grades 8 and 9

You are advised to page further and examine thesummary of the policy framework for Technology Grades4 - 9 before reading this synopsis. It will enable you to

gain an overall view of Technology in the schoolenvironment.

The two learning programmes (for Grade 8 and 9 respectively) are structured in terms ofLearning Outcome 2: Knowledge and Understanding.

The learning programme repeatedly covers the three areas indicated by the assessmentstandards of LO2, namely Structures, Processing and Systems and Control.

The learning programmes have been compiled in a way that exposes learners to asmany areas of technology as possible. Educators are often wary of moving beyond theboundaries of their own fields of knowledge, but you can rest assured that our package

will facilitate this because of the adequate amount of support material contained in it.

The learning programme for Grade 8 comprises four modules:

1. Structures (AS area - Structures)

2. Food Processing / (AS area - Processing)

3. Electricity / Electronics (AS area - Systems and Control)

4. Recycling

The learning programmes for Grade 9 comprise three modules:

1. Mechanical systems (AS area - Systems and Control)

2. Architecture (AS area - Structures)

3. Hydraulic and Pneumatic Systems

There is a constant focus on Graphic communication. With different aspects of graphiccommunication being built into every learning programme it is therefore not treated as aseparate section.

Learning outcome 1 (Technological Processes and Skills: Investigate, Design, Make,Evaluate and Communicate) and Learning Outcome 2 (Technology, Society and the

Environment) are not presented in separate modules. LO1 forms the basis for all theactivities in Technology and therefore also for all the modules in the learning programme.Throughout, the activities are also focussed on LO3 and this therefore is also included inthe modules.

Ensure that the critical outcomes that are relevant to education in South Africa areconstantly borne in mind. It would be wise to display these outcomes in the classroom,so that learners will also become aware of them. The relevant outcomes are listed inPart 1 of this guide.

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FRAMEWORKFOR TECHNOLOGYGRADES 4 9

LOs ASs 4 ASs 5 ASs 6 ASs 7 ASs 8 ASs 9

LO1

TECHNOLOGICALPROCESSES ANDSKILLS

Investigate

Design

Make

Evaluate

Communicate

Investigate

Design

Make

Evaluate

Communicate

Investigate

Design

Make

Evaluate

Communicate

Investigate

Design

Make

Evaluate

Communicate

Investigate

Design

Make

Evaluate

Communicate

Investigate

Design

Make

Evaluate

Communicate

LO2

KNOWLEDGE ANDUNDERSTANDING

Structures

Processing

Systems andControl

Structure

Processing

Systems andcontrol

Structure

Processing

Systems andControl

Structure

Processing

Systems andControl

Structure

Processing

Systems andControl

Structure

Processing

Systems andControl

LO3

TECHNOLOGY,SOCIETY ANDENVIRONMENT

IndigenousTechnology andCulture

Impact ofTechnology

Prejudice inTechnology


Impact ofTechnology



Impact ofTechnology



Impact ofTechnology



Impact ofTechnology



Impact ofTechnology


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Grade 8 Module 1

Time schedule

On average, 27,5 hours per week are available for physical instruction. Eight percent of this time, which comes to about 2,2 hours per week, must be allotted toTechnology. This should allow about three lessons per week, depending on howperiods are divided at your school. Our planning is aimed at 45- to 50-minuteperiods. Each year has approximately 40 weeks of school, including examinationtimes. Each of the modules (3 for Grade 8 and 3 for Grade 9) will requireapproximately 10 weeks for completion, which should make it possible to workthrough the programmes with relative ease.

Synopsis:

STRUCTURES

Week 1: Activities 1 and 2

Week 2: Activity 3

Week 3: Activities 4 and 5

Week 4 to 8: Activity 6

Week 9: Activity 7

Week 10:Activity 8

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MEMORANDUM

Structures

The learners became acquainted with the

theme of Structures in Grades 4-7. In Grade 4, thefocus was on strengthening structures by means offolding, the creation of tubular and triangularstructures and firm joins. In Grade 5, the emphasiswas placed on different kinds of structures and therelationship between the type of material and theload that a structure could bear. In Grade 6, thechoice of materials and reinforcement of structureswere investigated. In Grade 7, further attention wasgiven to the characteristics of specific materials,reinforcement, stability and techniques for creatingjoins.

In Grade 8, the above is continued. Thismakes it important for the educator to determinewhat the excising knowledge of the learnersencompass by means of questions, as they will befrom a variety of primary schools and may notnecessarily have gained equal insight and skills.Module 1 was written with the explicit aim ofsupporting the learner with inadequate knowledge sothat he/she would not feel altogether left out. Theemphasis is on the application of knowledge andskills, which means that the learner has ample

opportunity to be involved and that a fair amount oftime will have to be given to learner inputs and toassessment. In many instances, the educator mightwant to update activities.

Learner involvement may be facilitatedeven where no specific activities are suggested, byasking the learners to provide additional examples orto explain issues in greater detail.

.................ACTIVITY 1

The leaf (p. 1): Encourage the learners to mention further examples of naturalstructures and to record these in the vacant space surrounding the leaf. The sameis applicable to the crane on p. 2 and the examples used to illustrate particularfunctions (p. 2-3).

ASSIGNMENT 1

Consider letting each learner build a cardboard model of a house in advance.

Allow a fair amount of time for discussion of the learners' tables so that amaximum number of structures can eventually be listed. The list of examples

provided below is incomplete.

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ITEM CASING/FRAME FUNCTION

Walls Shell/casing Support, protection

Lintels Frame Reinforcement/strengthening

Door and window

frames Frame Support, bridging

Roof trusses Frame/casing Bridging, support

TV cupboard Frame/shell Protection

Roof Shell Protection

Door frames Frame Support

Railings Frame Support

Curtain rails Frame Support

Chairs Frame Support

Tables Frame /shell Support / bridging

Shelves Frame Support

.................ACTIVITY 2

Encourage the learners to illustrate the four types of force by means of additionalexamples.

ASSIGNMENT 2

1. Let the learners offer other ideas and discuss each idea (e.g. will a rectangular'pillar' be stronger or weaker? Will a slender double-walled pillar (with the paperoverlapping) be stronger than a more stocky pillar with single-layer walls?)

2. Let the learners decide which factors determine strength: e.g. more shallow foldsor fewer deeper folds, the type of paper, etc.

Allow sufficient time for learners to name examples from their daily environment. The

class could discuss the examples and suggest improvements.

.................ACTIVITY 3

ASSIGNMENT 3

Square: A triangle provides the strongest reinforcement; a single diagonal beam inone direction will be stronger than any other kind of reinforcement.

Triangle: Which of the beams in the illustrated structure bears the most weight?

Do all the beams bear equal weight? Let the learners decide. How could this betested? Remove beams in turn and check whether the structure is weakened.

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Learners could also use pipe cleaners to represent a bicycle frame. Let thelearners name further examples and allow class discussion.

ASSIGNMENT 4

1. Which factors determine the strength of the strut? The thickness of the strut, thejoins and the distance between the joins and the ends.

Encourage the learners to list examples in common practice and discuss this.

2. The forces of both stress and compression. Force from above causes verticalcompression (right down) and stress on the rope (horizontal) to keep the legs fromshifting. If the force is not applied from above but from the side, one of the legswill be able to move. It can be rectified by replacing the rope with a solid bar.

.................ACTIVITY 4

1. The learners must draw lines by linking dots. An additional suggestion: work from

both dots for lines to meet in the middle (By doing this, it is less likely that the linewill miss the dot).

2. and 3. Suggest that learners practise drawing straight freehand lineson loose sheets of paper.

4. and 5. Bear in mind that these are freehand sketches. Adequateopportunity for practising freehand drawing on loose paper is thereforeimportant. Also encourage learners to practise in context, e.g. by drawingthe wheels of a vehicle, etc.

.................ACTIVITY 5

Allow learners to discuss beams, pillars, struts, crossbeams and anchor lines andto list examples. Let them explain where the stresses are exerted and what theapplication of a specific structure is, why it is suitable for the application and howit could be improved. In the case of a crossbar, the stress, for instance, is exertedbelow; a pillar bears vertical stress that is equally strong all over.

ASSIGNMENT 5

It is important to use correct terminology when discussing examples:

Bow and arrow:

Problem: It was necessary to hunt to get food. Animals could not be caught by hand. Itbecame necessary to design a weapon.

The bow and arrow as a structure: The string is used to exert the force of stress on thebow. The bending of the bow makes it possible to transfer this force to the arrow as theforce of compression. The arrow, as a beam, causes the force to work in the directionof the arrow point to penetrate the prey.

Crossbow

Like the bow and arrow, but more accurate and more powerful.

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Shield and spear

The spear serves as a beam, which means that the force is exerted in the direction ofthe point, which can therefore penetrate the prey. The shield forms a shell structure,with the skin as shell and the wood as a frame.

Sword

The blade works as a beam.

Ordinary hut

A shell structure, with the woodwork as frame and the grass as shell.

Rondavel and thatch-roofed houses

Like ordinary huts, but with the clay forming part of the shell.

ASSIGNMENT 6 Skyscrapers: larger numbers of people are able to inhabit a specific space.This facilitates urbanisation and makes demands on urban transport, sewerage,electricity supply, removal of storm water: problems that had to be solved by means oftechnology and have created job opportunities, which lead to further urbanisation.

Aeroplanes: great distances can be covered in brief periods of time, whichmeans that both people and goods can be transported quickly. This, however, hasimplications with regard to pollution and the utilisation of natural resources. It alsoincreases the tempo of living.

Roof trusses: For people who live in inhospitable climatic regions, rooftrusses prevent roofs from collapsing when there are heavy snowfalls and hail.

Railway lines and trains: As with aeroplanes, but trains have also enabledpeople to spread civilisation across the globe.

Bridges: as with aeroplanes and trains.

.................ACTIVITY 6

Refer to the framework included in the module for the assessment of the work. Youcould extend the framework to meet all possible portfolio requirements, e.g. byordering research results by means of tables and by means of graphicpresentations.

.................ACTIVITY 7

Ensure that the learners are given sufficient opportunity to master this importantdrawing skill. Neatness is particularly important and the use of light constructionlines and basic sketching skills (Activity 4) will enable the learner to meet these

requirements.

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Grade 8 Module 2

Food Processing

Overview / Memorandum

.................ACTIVITY 1

Introduction:

The module deals with food processing. Seeing that only a few schools have thenecessary facilities to cook food, a fast-food dish has been chosen as learners canprepare it at home and put it together in the classroom. It would be very helpful if amicrowave oven were available during the production process. Learners must beencouraged to develop sound business principles during the course of this module. It isfor this reason that entrepreneurship is emphasized. The module could also be linked topossible market days.

1.1 Processing can involve any material or product that undergoes a process in order to forma new product. That entails the processing, combining, colouring, packaging, etc. ofmaterials and products.

1.2 Any example that is distinctive of your environment, e.g. grapes to wine, wheat to bread,etc. can be used.

.................ACTIVITY 2

Use the pictures for this activity. The pictures have been jumbled and must be organizedin the tables that follow them, as indicated in this memorandum.

The function of each piece of equipment must also be written down.

GROUP 1: MEASURING UTENSILS

UTENSIL(S) FUNCTION

1. Measuring spoons To measure small amounts of liquids or dry ingredients.

2. Measuring cup To measure small amounts of dry ingredients.

3. Measuring jug To measure liquids and dry ingredients.

4. Scales To measure dry and solid ingredients.

GROUP 2: MIXING UTENSILS

1. Mixing-bowl To mix cake mixtures and mixtures for scones, bread or biscuits.

2. Wooden spoon To stir or beat starch or milk mixtures; to rub ingredients througha sieve.

3. Spatula To fold stiffly beaten egg whites into a mixture; to apply icing; toturn flapjacks.

4. Dough scraper To scrape mixtures out of bowls, dishes and saucepans so thatthere is no wastage; to scrape leftovers out of plates and dishesbefore washing the dishes.

5. Balloon whisk To beat (whisk) eggs and other liquid mixtures.

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GROUP 3: COOKING UTENSILS

1. Saucepan To cook, steam or simmer food; to make sauces or gravies;to cook jam.

2. Double boiler To cook food by steaming it, e.g. egg custard, rice or fish.

GROUP 4: BAKING- AND GRILLING UTENSILS

1. Baking tray To bake scones and biscuits.

2. Bread and cake tins To bake cakes and bread.

GROUP 5: SUNDRIES

1. Sieve To sieve flour and dry ingredients.

2. Colander To drain rice and vegetables, to wash lettuce and other vegetables.

3. Grater To grate vegetables, cheese, nuts, orange peel.4. Kettle To boil water.

.................ACTIVITY 3

Allow learners to write down their own rules, present them to the class and then respondto the reactions from the class.

.................ACTIVITY 4

4.1 Keep sharp knives out of childrens reach.

Cut away from yourself when using a chopping-board.

Do not allow pets in the kitchen.

Keep curtains away from the stove.

Do not wear garments with long or wide sleeves when you work at the stove.

Mark containers that contain foodstuffs and cleaning agents clearly.

Mark poisons clearly and keep them out of reach of children.

Roll broken glass in layers of newspaper before placing it in a rubbish bin.

When passing a knife to someone, present it with the handle pointing towards therecipient.

Do not run and play in a kitchen.

4.2 Turn pot or pan handles away from the edge of the stove.

Do not leave the kitchen while there is hot oil on the stove.

Use dry potholders, not wet cloths.

If oil should start burning, place a lid on the container; do not pour water on oil.

Lift the lid of a pot in such a manner that the steam escapes away from you.

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4.3 Do not use damaged electrical cords.

Turn power off after use.

Do not handle appliances with wet hands.

Keep electrical cords away from hot appliances. Have repair work done by qualified person.

.................ACTIVITY 5

5.1 Apply pressure to the wound.Keep the wound high.

5.2 Burn wounds caused by dry heat, e.g. flames.Burn wounds caused by moist heat, e.g. steam and boiling water.TreatmentReduce the heat by applying ice or cold water to the affected area as speedily aspossible.

5.3 Sleeves must be rolled up at all times.Use a thick, dry cloth with which to handle hot utensils.Pan or pot handles should not protrude from the edge of the stove.A fire blanket and fire extinguisher should be kept in every kitchen.

5.4 The sketch is a summary of all the safety measures that have been dealt with thus far.Allow a class discussion on the learners contributions.

.................ACTIVITY 6

6.1 Each learner has five pages with diagrams such as the one shown below. Allowthem to exchange information by means of presentations.

Food Group

EXAMPLES

MAIN NUTRIENT

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FUNCTIONOF MAIN NUTRIENT

...........................................................................................................................................

...........................................................................................................................................

6.2 Examples of goals:

Eat less sugar.

Eat less fat.

Eat less salt.

Eat more fibre.

Do not overeat.

Eat a balanced meal.

.................ACTIVITY 7

This activity covers the technological process. Learners can work in groups of 2 or 3.Groups can draw a map of the country they will represent. Countries such as Spain,Greece, Mexico, the USA, the RSA and France all have well-known fast foods. Makecards with the names of the different countries on them and let the learners draw.

The idea is that the learners will plan and erect a fast food stall for the show.

Diet

Sweets?

Is that the price of

sugar-free sweets?

i eat just enough food and food with a

lot of fibre

I avoid all food with salt.

or with fat wow!How do you

feel?Hungry!

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7.1 The activity can be done on an A4 page. The name of the members of the company, thename of the business and the logo of the business must appear on the page.

7.2 Compare the staple food and fast foods of two countries / cultures. A class discussion /summary on the board in order to summarise all the countries staple foods and fastfoods, will be very useful.

7.3 Photocopy the research pages and give them to the learners to be completed. It isimportant to give the learners sufficient time for research seeing that a great deal of theresearch must be done at the businesses themselves.

7.4 The group must produce ideas of possible fast foods in order to select a final fast foodproduct.

7.5 During their planning, learners must keep in mind all the facets that have been mentionedin the module. Special emphasis must be placed on the costing and the selling price ofthe product. Learners will thus be able to calculate the profit per item.

7.6 Seeing that it is a group presentation, the learners must be thoroughly prepared.Therefore it would be meaningful for the learners to complete a flow chart to illustrate

their production line. Encourage learners to decorate their stall (table) and to have aposter with a sketch of their product and its price.

7.7 If you have the necessary facilities, you could allow the learners to prepare their food inclass, but you would have to give them extra time. The other option is that the food canbe prepared at home, and only be assembled during the presentation.

7.8 Learners can write their own evaluation by reading the specifications again and usingthem as criteria. Learners can evaluate the taste, texture and appearance, and makerecommendations and improvements.

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ANEVALUATIONSHEETSUCHASTHEONETHATHASBEENATTACHEDCANBEGIVENTOTHEPANEL:

COMPANY:

MEMBERS:

TIME:

Final product: MARK OUTOF10

CULTURALLINK

NUTRITIONALVALUE

ORIGINALITY

QUALITYCONTROL

PRODUCTIONLINEEFFECTIVENESS

PRESENTATION

COMPANYSPIRIT

TIDINESS/HYGIENE

PRICECONTROL

TOTALIMPRESSION

TOTAL MARK (out of 100):

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Grade 8 Module 3Electricity

Synopsis of the Module

Most learners take having electricity in their homes for granted. A class discussion couldaddress the following:

How people who have no electricity manage. We are referring to the use ofearth ovens, open fires, solar cooking apparatus. Learners who are privilegedenough to have electricity in their homes, often do not realise what the costs are.

The cost of electricity: Electricity is provided to us in kilowatts (kW). Theaverage cost is 39 cents per kilowatt-hour (kWh). If you use 5 kilowatts' worth ofelectricity in an hour, it will cost you 5 x 39 cents. Nowadays, many homes areprovided with apparatus for pre-paid electricity and electric power is paid for inunits. The apparatus indicates how many kW-hours worth of electricity is still

available for use.

The difference between direct current (DC) and alternative current (AC).Alternative current is the power used in our homes. It is generated in variousways, e.g. in nuclear power, hydroelectric power, or coal power stations, or fromwind or solar power. A consistent 220-volt (V) current is generated in SouthAfrica. Many electrical appliances have transformers to decrease the currentbecause this voltage is too high.

Direct current comes from batteries and electric cells. The current isobtained from a chemical reaction within a battery. When a battery is flat it isunable to convert chemical energy into electrical energy. Many batteries, e.g. carbatteries and cellular phone batteries, can be recharged.

CIRCUITCOMPONENTS:

Battery: One of the easiest batteries to use as a source of electricity in the classroomis the PP3 battery that generates 9 volts. It is particularly suitable as it has aclamp that can be fitted to the poles quite easily. The battery also has a red wirethat is positive and a black wire that indicates the negative charge. This willenable learners to build circuits and the educator to test all the different currentswith one battery, by simply connecting all the learners' circuits to the battery.

9V

+

Symbol

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If educators should prefer using a 220V alternating current as power source, atransformer will have to be used to transform the alternating current to a 9V directcurrent. Appliances for doing this can be bought, but are also easily constructed ifone has the necessary technical knowledge.

The advantage of such an appliance is that it can be used over a long period of

time. It incorporates a safety mechanism to deal with the possibility of a learnerinverting the polarity. The sketch below represents such a circuit. It is possible toobtain casings for such appliances from suppliers of electrical appliances.

Resistors offer resistance to the flow of current in the same way that a tapdetermines the force of the stream of water. Resistors have fixed values, butadjustable resistors can be set. It is important to know that all other componentsalso offer resistance to the flow of the current.

The value of a resistor is indicated by means of a colour code on the resistor. Thefirst three bands indicate the numerical value and the fourth indicates the accuracyof the resistor. Resistance of 1 K is 1000 Ohm. The colour code will have thefollowing colours: Brown (1), black (0), red (00). The following chart is generally

used in practice. It is advisable to have an actual chart in the classroom.

The resistor colour-code chart

Accuracy band

Example question:

Find the value of theresistor shown below

brown black redband band band

Answer

Brown band = 1Black band = 0Red band = 00

= 1 & 0 & 00= 1 000 ohmsof 1K ohms

Colour Zeros

Black 0 0

Brown 1 1 0

Red 2 2 00

Orange 3 3 000

Yellow 4 4 0000

green 5 5 00000

Blue 6 6 000000

violet 7 7 0000000

grey 8 8 00000000

white 9 9 000000000

LIGHT-EMITTINGDIODES (LEDS)

A diode is a component that allows the current to flow in one direction only. It works onthe same principle as one-way water valves. The triangle in the symbol indicates thedirection of the current, while the line indicates the side at which the negative end of thebattery should be linked.

Resistor

Value bandsAccuracy band

Symbol

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A diode emits heat when a current flows through it. Light-matting diodes emit lightand are commonly used in appliances. They are available in a range of colours,like red, yellow, green and even blue. If a learner should want to make a set ofChristmas lights, a flickering LED can be linked. One such LED will induce aflicker in a whole range of LEDs if they are linked in series. LEDs cannot be linked

directly to a 9-volt current because this would lead to a blow out. A resistor shouldbe linked before the LED to protect it.

LED = Light Emitting Diode

n LED = 1.2 volt guestroom +/-

Switches

Many different switches are available. The sketches show several switches, aswell as a simple model that could be built to illustrate the workings of a switch tothe learners.

Push to make switch

Toggle switch (stays on once pushed)

Side switch

Switches can be linked in two ways:

(AND): logical gate: If switches A AND B are closed, the light bulb will glow.

Paperclip

bent up

Wire

Drawing pins

Wood

Push clip down

Slide sideways to make contact

Wood

WoodSlide sideways to either position

Symbol

symbol

Symbol

A B

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OR: logical gate: When switch A OR B is closed, the light bulb will glow.

Building circuits:

Electric boards are ideal for building circuits. These boards have holes so thatcomponents can be fitted or removed with ease. Some holes are linkedhorizontally, while others are linked vertically. It is important to avoid placing allthe components in the same circuit, as this will result in the current following theline of least resistance, and the components will fail to work.

When learners have built their test circuits, the final circuit can be built on stripboard. Strip board can be cut to provide smaller sections quite easily (with a metalsaw or NT cutter), so that learners can obtain the required sizes. A simple circuit,with positive and negative wires, a switch, a resistor and a LED could beassembled on a board of 20 cm x 20 cm. A drill bit can be used to break thecopper circuits where necessary at the back of the board.

A

B

Horizontally linked holes

Vertically linked holes

Dividing the board

Copper strips

Holes

Insulation

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Figure A

If your school does not have electric boards or strip boards, you may build circuits onwooden boards by making use of the following techniques:

Attaching wire to components:

Wind wire by hand and twist to attach to screw.

Building switches:

Making holders (sockets) for light bulbs:

Variable

resistor

Battery

Circuit board

Light dependent

resistor

Bulb

'Flying leads'

Foil wrappedaround peg

Wood

Paper clip

Paper Clip wire twistedaround light bulb

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Use screws on wood

Joining wires:

Building a circuit on a wooden board:

STEP BY STEP THROUGH THE MODULE

.................ACTIVITY 1

Showing knowledge and understanding of the electrical circuit, LO2.4

its origin and its positive and negative impact on the environment. LO3.2

The emphasis should be on the origin of electricity, namely the atom. Learners shouldalso become thoroughly acquainted with the difference between AC and DC.

Assignment 1

1.1 Emits light and warmth. Can be used in electrical appliances, e.g. TV sets,computers, etc.

1.2 AC

1.3 220V

1.4 ESKOM

1.5 Nuclear power stations, hydroelectricity, coal-driven power stations, wind turbines.

1.6 Nuclear power: nuclear waste; radiationHydro power: disrupts ecology

Coal: smoke pollutionWind turbines: intrudes on the landscape

1.7 The emphasis should be on power lines, substations and transformers.

Chocolate board Crocodile clamp

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.................ACTIVITY 2

Becoming acquainted with safety precautions concerning electricity. LO1.12

Learners should gain a thorough understanding of the dangers of electricity. If electricity

is not used with the necessary caution, its use can be fatal. In Focus Task 1, you coulduse electric wire without a power supply. All learners should be given an opportunity toplug in a power plug/wall plug.

Assignment 2

2.1 Do not overload wall plugs.Ensure that electrical; cords are in good condition.Avoid using electricity near water.Avoid joining electrical cords.

2.2 Switch off the power supply.Use non-conducting materials to free the person from the power supply and pull the

victim away by his/her clothing.If the victim is unconscious, mouth-to-mouth resuscitation should be applied.

2.3 L brownN blueE green and yellow

2.4 If there is accidental contact between the parts of the appliance that carry theelectrical current and the cover of the appliance, it is necessary to lead the current tothe earth to avoid an electrical shock if anybody should touch the appliance.

2.5 Learners' own attempts.

.................ACTIVITY 3

Demonstrating basic knowledge of circuits, conductors and insulators anddrawing a diagram of a circuit. LO2.4

Practical testing dealing with Systems and Control. LO1.3

Drawing a diagram of a circuit. LO2.1

Assignment 3

Build the following circuit. Two clamps could be used for holding components in position.The results should produce the following:

ITEM MATERIAL ISOLATOR CONDUCTOR

Ruler Perspex Yes No

Nail Steel No Yes

Paper Clip Copper No Yes

Wool - Yes NoCardboard - Yes No

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Tin foil Aluminium No Yes

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Assignment 4CIRCUITS

4.1

4.2 Heating: heater, hot water cylinderMagnetic: electric motor, domestic doorbell, indicator lights of a car,Chemical: swimming pool chlorinator, covering objects in metal/electrode

.................ACTIVITY 4

To know the most important electrical units and to understandthem. LO2.4

The following definitions are important:

Electric current: Flow of electrons in a closed circuit

Voltage: Electromotive force that enables the flow of electric current

Resistance: Quality of materials offering resistance to the flow of electric

current. Power: The energy that a battery has to provide and which is used in a

resistor.

Ohm's law:

This states that the current passing through a resistor is directly proportional to thepotential difference, or voltage, across the resistor, i.e. the current is directlyproportional to the linked voltage and inversely proportional to the resistance.

Assignment 5

An easy way to remember the following:

5.1 V = I R and R = V/I

5.2 V = P/I en I = P/V

5.3 R = V/I

= 5,1

3

= 2 ohm

1,5 V

Light bulb

Crocodile clamps

I R

V

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5.4 P = V I= 3V 1,5A= 4,5 watt

.................ACTIVITY 5

Gaining knowledge about series and parallel linking by means of practicaltests. LO1.3

Learners have to discover this through practical experience. Many schools still havewooden boards that are suitable for this practical exercise. The breadboards are alsovery suited, as circuits can be built very quickly. In this instance, LEDs can be used inthe place of light bulbs. This also provides an ideal opportunity to use the MultiMate.Learners could take readings while they are working.

Note that the long arm is positive and the short arm negative. The components thereforehave to be linked correctly and be protected by a resistor.

Assignment 6

6.1 a) 1,5 V + 1,5 V = 3 V

b) The output glow is duller.

6.2 a) 1,5 V

b) No noticeable effect, but battery will discharge faster.Dull

6.3 a) The others do not glow.

b) All glow more dully.

c) 3 V (if the input is a 3V battery, there is no resistance)

6.4 a) The other one continues to glow.

b) All will glow equally brightly.

c) 3V (if input is a 3V battery, there is no resistance.)

6.5 a) It protects the LEDs in the circuit.

b) R1 + R2 = RT (formula for serially-linked resistors)

FOCUS TASK3:

Mastering the skill of soldering LO 1.10

Soldering:

The following sketch illustrates the basic requirements for soldering. The solderis an alloy of lead and tin. It contains its own flux which allows the solder to flowfreely.

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Situation 1

The following examples provide an idea of what the learners' ideas should leadto (a wooden board of 150 mm x 60 mm x 22 mm could be used as a base). Iflearners wish to add a background, a saw may be used to cut a 3-mm groove inthe board, for inserting a piece of hardboard as backing. Motifs that suit thewiring (theme) may be painted on this background, or suitable pictures may bepasted on it.

Situation 2

Learners could make use of waste containers, like plastic bottles, to cut outmotives, e.g. a pair of lungs, and draw in details using fibre-tipped pens withpermanent colours. The circuit could be built on strip board, using long wires forlinking the battery, so that the battery can remain outside the bottle. The circuitboard can be inserted into the bottle if the back of the bottle is cut open.

In both instances learners have to identify and formulate the problems that arise inthe given situation. They have to write their own design proposals and the educatorcould stipulate specifications according to the nature of the class, materials,equipment and available components. The learners' ideas might include differentcircuit layouts as well as different designs. The educator will have to evaluate their

models accordingly. Each learner has to produce a portfolio and design a cover page for it.

The following steps have to be followed during soldering:

Ensure that no movement occurs where the wires are being joined (a "third hand"will be needed).

Heat the join with the soldering iron.

Place some soldering flux on the join.

There should be a shiny join when the wire has cooled down.

Soft solder often supplied

on a reel

Flux (in the centre)

SOFTMULTICORE

SOLDER

Soldering iron

Soldering iron

holder

Wire cutters

Damp sponge used to clean

soldering tip

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Take note:

The surfaces to be joined must be clean.

Allow 3 to 5 seconds for the heating of the join.

Use a soldering iron of appropriate size for your work.

A practical suggestion: When two wires are to be joined by soldering, the two separateends could be soldered before being joined together this is known as sweating. Useold printed circuit boards (PCBs) for practising soldering.

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Grade 8 Module 4

Table Of Contents

In this module the learner will do the following:

Activitynumber What he/she will do

LOnumbe

r

1. Demonstrate knowledge and understanding of what recycling

is, and the route that waste should go.1.1

2. Perform tests to see what materials and what quantities of

waste are generated at home in order to form an opinion aboutthe impact of products of technology on the quality of peoples

lives and the environment in which they live.

3.2

3. Demonstrate an understanding of how materials (plastics) can

be recycled.

2.2

4. Demonstrate an understanding of how materials (glass) can be

recycled.

2.2

5. Demonstrate an understanding of how materials (paper) can be

recycled.

2.2

6. Demonstrate an understanding of how materials (metals) can

be recycled.

2.2

7. Form an understanding of what incineration and landfills are

and understand the positive and negative impact of these on

the environment.

3.2

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.................ACTIVITY 1

1.1 Recycling: Collection, processing and re-use of materials that would otherwise bethrown away.

1.2 Shop Home Bin Waste bag Landfill

1.3 Shop Home Recycling bins Process of recycling

1.4 Emblem

1.5 Using recycled materials makes new products cost less.

Requires less energy to make products with recycled materials.

Reduces air pollution.

Decreases the amount of land needed for waste dumps.

Conserves natural resources by reducing the need for new material.

.................ACTIVITY 2

Through this activity the learners will collect data and process this data. Learners mustbe motivated to do this at home so that they can discover how much recyclable materialwe throw away daily. They can copy the tables in MS Excel which will make it easy toillustrate the data in a graph.

.................ACTIVITY 3

Plastics are divided into two main types thermo softening and thermosetting. Thesenames refer to what happens when plastic materials are subjected to heat.

Thermo softening plastics become soft and pliable when they are heated and hardenagain when cooled. This process can be repeated again and again. Examples are PVC,Nylon and Polythene.

A thermosetting plastic, on the other hand, can be moulded only once - during themanufacturing stage. These plastics are used for heat-resistant objects, such as lightfittings, saucepan handles and kitchen work surfaces.

3.1 something that does not decompose naturally

3.2 cool drink bottles, margarine containers, milk bottles, etc.

3.3 cheap, light, durable, coloured easily, etc.

3.4 One of the problems is that any of seven categories can be used for containers alone.For effective recycling, the different types cannot be mixed. The recycling process isalso very expensive, for the plastics must first be washed, then shredded into flakes,then the flakes are melted into pellets. For health reasons, recycled plastics are rarelymade into food containers.

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.................ACTIVITY 4

4.1 It is transparent, fairly cheap to manufacture, easily formed into bottles and jars and

easy to recycle. Special glasses for people with sight problems, as well as mirrors aremade.

4.2 It brakes easily and has sharp edges.

4.3 Windscreens are made from laminated glass (glass sandwich) with a layer of plastic inthe middle. Other kinds of strong glass include wired glass and bulletproof glass.

4.4 If molten glass is forced through a small hole it can be drawn into very fine fibres whichare known as fibreglass. These glass strands are made into thick mats which can beused for several purposes. Glass fibre is used in building boats, and for isolation inhomes, etc.

.................ACTIVITY 5

More than half of the worlds timber is burnt as fuel, most of it within a few kilometres ofwhere it is felled. Half of the worlds population use wood for all their cooking andheating. The rest of the worlds timber is used in industry for building and paper-making.Most paper is made from soft woods. However, 50% of the wood pulp used to makepaper comes from waste wood from the sawmill.

5.1 Deforestation: the cutting of mature treesRe-forestation: Replacing trees at the same rate at which they are cut down

5.2 Hardwood: Teak, Walnut, Ebony, Oak

Softwood: Pines, Spruce

5.3 Stinkwood (or other indigenous wood)

5.4 Tropical climate, rain throughout the year, mountain range

5.5 In the winter the tree grows slowly and forms a dark ring while in the summer it grows fastand forms a wider and lighter ring. Together the two rings indicate one year of growth.

.................ACTIVITY 6

6.1 Copper, stainless steel, aluminium, brass, gold, nickel, etc.

6.2 Rods, pipe, tubes, angle-iron, I-beams, sheets

6.3 Beans, beef, corn, peas, fruit, etc.

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.................ACTIVITY 7

7.1 Incinerators: Require less land, and will pollute ground water

Landfills: Prevent waste from blowing away, keep down odours

7.2 Incinerators: Air pollution and expensive to operate

Landfills: Pollute ground water, uses large areas of land

7.3 For incinerators to be profitable you need all the rubbish you can get. Municipalitiestherefore send all their waste to this machine to keep it running.

Situation:

How to make a lampshade:

1) Mix the starch according to the instructions on the pack. Note that all the starch mustbe used, for it cannot be kept.

2) Place the mould, e.g. a bowl, upside down and apply margarine all over it. Tear paperstrips and paste them with starch around the bowl, allowing the edges of the squares tooverlap.

3) Tear more paper strips and cover the rest of the bowl. Tear a circle of paper and paste

it on the centre to round it off neatly. Apply at least two layers of paper and allow it todry well.

4) Apply a thick layer of starch over the covered area. You can make patterns on the wetstarch. Allow to dry well and slip the lampshade carefully off the bowl and allow to dry.

5) You can now spray-paint the shade.

6) Cut a hole in the top centre of the shade, just large enough for the flex and bulb holderto pass through.

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Synopsis Grade 9 Module 1

Mechanisms and Motion

This module focuses on Systems and Control. Other foci in this

field are Pneumatics, Hydraulics and Electronics.

There are not many educators who actually have any background in the field ofmechanisms. It forms such an important part of the curriculum, and in our daily lives, thatour learners should be enabled to master knowledge and understanding of mechanisms.

Videos are available from the Mechanical Theatre in the United Kingdom. Unfortunately,such videos are not freely available in South Africa. If you should have an opportunity tovisit the theatre at Covent Gardens in London, you should do so to experience thewonderful world of mechanical toys.

Plastic mechanisms are available from several manufacturers of plastic products, though.Although these are expensive, they are useful for demonstrating different mechanisms.Technical sets like Techno-Lego are also suitable for use in demonstrations.

This module covers the theory of basic mechanisms and the activities test the learners'knowledge and understanding in this regard. In all, the theory and activities should take10 lessons of 50 minutes.

At the end of the module we offer a challenge in the form of two scenarios. The firstscenario requires the learner to design and make a mechanical tool that an educatorcould use to demonstrate a specific mechanism. Learners have to develop a projectportfolio to show their progress. The educator has to decide which materials the learnersmay use for their products.

The second scenario offers a bigger challenge: the learners have an opportunity to designa new product or improve an existing product. Together, the two scenarios will take 10to12 lessons to complete. The total amount of time needed for this module will thereforecomprise 20 hours of instruction time.

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The following illustrations offer information in broad terms about what the educatorwould be able to use to develop mechanisms.

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.................ACTIVITY 1

Learners could list any product that they regard as a mechanism. The aim of theactivity is to help the learners to become aware of how many products actually aremechanisms. Discuss their examples in the classroom.

.................ACTIVITY 2

2.1 Greater forces can be transferred

2.2 Chains do not slip/slide

2.3 Chains can be unlinked to facilitate removal

.................ACTIVITY 3

Door handle Oscillating (handle) and backwards and forwards-movement(reciprocating)

Tap Rotating movement

Air pump Oscillating

Pair of scissors Oscillating

.................ACTIVITY 4

4.1 A Crank(-handle)

B Gears

C Propeller/screw

D Pulley

E Linkage/linking

F Cam

4.2 Tricycle

4.3 Three times slower (15/5 = 3)4.4 Store air-tight/Keep things tightly stored

4.5 Twist the rubber ring to form an 8.

4.6 Any cam-driven toy

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.................ACTIVITY 5

Use cardboard strips to test if there is any doubt

Linkages

Output DirectionAdd output direction arrows

Output DirectionAdd output direction arrows

1. 1.

2. 2.

3. 3.

4. 4.

5. 5.

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.................ACTIVITY 6

6.1

6.2 Moment = force x distance between force and fulcrum

6.3

6.4

31

3

N100

N300

Effort

LoadMV ====

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6.5 SV =loadofmovementofDistance

effortofmovementofDistance

=mm200

m1

= cm20

cm100

=1

5

= 5:1

6.6 Work input (for movement over distance of 8 metres) 50 x 8 = 400 Nm

(NM = Newton-metres)

Work input (for movement over distance of 4m) = 80 x 4 = 320 Nm

Effectiveness =inputWork

outputWork

=400

320

= 0,8

= 80%

.................ACTIVITY 7

7.1 1.

2.

3.

4.

5.

6.

7.

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7.2

7.3 Drilling machine, Block and tackle

7.4 1.1

1250

4

80 = 250 ohm

2 Insert idling gear

7.5 Advantages of tooth gears and chains

1. Greater forces can be transferred

2. Chains do not slip/slide

3. Chains can be disassembled for removal

Advantages of pulleys and belts

1. Belts are not noisy

2. Belts can be stretched for fitting and for removal

3. Crossed belts can change the direction of rotation

.................ACTIVITY 8

8.1

8.2

8.3 Crank-handle ------- crankshaft / tricycle

Cam ------- Cam on camshaft

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.................ACTIVITY 9

9.1 Screw and crank-handle

9.2 First kind of pump. Worked manually, electricity not available. Rivers were the mainsource of drinking water no taps in houses.

9.3 Pumps used in bore-holes.

9.4 For this essay, learners have to do research on how mechanisms have been used tofacilitate the improvement of the waste industry. They also have to determine thepossible effects on the environment.

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Overview Grade 9 Module 2Structures

Architectural Planning

This module is an extension of module 1 grade 8. It focuses mainly on Learning Outcome1 and 2 and in particular assessment standard 1.9 where the learners must make formaldrawings showing dimensions. The formal drawings are orthographic, oblique and areaplans. The curriculum allows us to choose between isometric and oblique. If you chooseto do isometric rather than oblique due to your technical background you can do so. Thedrawings form part of graphical communication Assessment standard 1.15.

Focus task A

1. Learners must show a clear understanding of what a structure is. Activity 1 explainswhat a structure is.

2. Any structure from natural to man-made example. Houses, roofs, birds nests, bicycleframe, caves, etc.

3. Supports ladder, chairsProtects House, birds nestsContains - Swimming pool, shopping bagSpans distances bridge, washing line

Focus task B

1 Dam walls, reservoirs

2 Bicycle frame

3 Electric power supply tower

4 Car, e.g. Volvo

5. This sheet must contain information on sheet material such as glass, board products,metal products which are used by builders nowadays. The learners need to do researchon this assignment.

6. The term means that a material has been made stronger by adding a material of strengthin its structure. In most concrete buildings these days metal rods reinforce the concrete.

7. Reinforced concreteWood, e.g. plywoodGlass that contains metal strips

.................ACTIVITY 3

Learners are expected to work in groups of 2 to 4. It will be necessary for the learners togo to the site where they plan to build the new classroom. They must do an analysis ofthe new site. This analysis will be evident in focus task C. They can take paper to thesite to make notes and write down measurements (measure your steps: 1 step = 1metre). The learners must then use this data to produce a formal sketch of the site inclass (Focus task C).

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They must also write their own design brief and specifications for their classroom in Focustask C. The brief must be something simple, like Design a new classroom for the newgrade 8s.

The specifications must be the requirements for an ordinary classroom, including the

following: the size - 40 learners must fit in comfortably

ventilation

lighting (electric and natural)

materials

number of desks

shape of classroom

blackboard?

doors, etc.

The learner is forced to do research in Focus task D. They must gather data through aquestionnaire and must present this data in the form of a graph. If you have computersavailable this presentation can be done in programmes such as Excel and PowerPoint.

The ideas must be 3 dimensional in the form of oblique or isometric. Use the grid paperprovided. The learners can place a clear sheet of paper on top of the grid so that theycan use the grid over and over again.

The following focus tasks all involve graphical communication. It is important toemphasise neatness and tidiness when it comes to formal drawings. If you haveexamples of block plans, house plans or even the plan of the school available, it will helplearners to comprehend what it is all about. The concept of scale is always confusingand must be explained with care.

Focus task H and I must be done thoroughly. The attached example will indicate to youwhat the desirable outcome must be. If you do not have any background on orthographicdrawings it is advisable to use a woodwork textbook or even ask the woodwork ortechnical drawing educator on this issue.

This module allows learners to design a classroom in many ways and through differentgraphical methods. Although the group produces only one scale model, every groupmember must have his own portfolio. In the end their final idea must be realistic so that

they can make a scale model from cardboard. Cardboard is very easy to use, since youonly need tools like safety rulers, cutting knives, glue and scissors. The learners canleave the roof or just part of it open to show their layout on the inside. It is advisable thatthe learners plan their manufacturing by producing a flow chart of the manufacturingprocess.

Since the learners are all familiar with classrooms they are the best persons to use forevaluating the final products. This evaluation can be done in the form of a presentation just like an architect will sell his plans to a company.

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There will be better propagation of the pressure in the cylinder.

The density is greater and the force/power will therefore be propagated betterthan in water.

.................ACTIVITY 5

1. 2 cm at A and B respectively

2. The output of two 10-ml syringes each filled with 5 ml of water will be the same as theoutput of one 20-ml syringe containing 10 ml of water. The larger 20-ml syringe cancontrol two 10-ml syringes if it contains twice (2 x 10 ml) the amount of water.

SYNOPSIS: ACTIVITY 1 5

A small force on a small piston/plunger produces a great force on a largepiston/plunger.

A small piston/plunger will move over a large distance and a large piston/plunger

over a small distance.

The larger piston/plunger is able to control a number of smaller pistons/plungers if itsvolume is equal to the sum of the volumes of the smaller pistons/plungers and theamount of water in the larger piston/plunger is equal to the combined volumes of thewater in the smaller pistons/plungers.

.................ACTIVITY 6

1.1 FORCE = 2 N

1.2 MA=1/2

1.3 1,5 cm

1.4 No, the small piston/plunger will move the furthest and enable Jack to make thehighest jump

2.1 The piston/plunger with a diameter of 1 cm

2.2 1,5 cm

.................ACTIVITY 7

1. Prevents the reverse flow of the liquid/fluid so that the piston/plunger remains in

position and the pressure is maintained.

2. When the lever moves upwards, a small amount of oil is released from the reservoir tothe small cylinder.

When the lever moves downwards and input force is brought to bear on the smallcylinder, the oil flows through the one-way valve to the large cylinder. The pressureis propagated through the liquid according to Pascal's principle and provides a greatoutput force on the large cylinder.

When the lever is raised again, the one-way valve shuts and the oil is unable to flowback. This maintains the power advantage. The process is repeated from thebeginning.

tg_ tech_ gr 8_ 9

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