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Time: 2 Hours Marks 150 This question paper consist of 10 pages including cover and information sheets

MECHANICAL TECHNOLOGY

JUNE 2015

NATIONAL

SENIOR CERTIFICATE

GRADE 10

Mechanical Technology Grade 10 MDE JUNE 2015

2

INSTRUCTIONS AND INFORMATION 1. Read ALL the questions carefully. 2. Answer ALL the questions. 3. Number the answers correctly according to the numbering system used in

this question paper.

4. Start EACH question on a NEW page. 5. Show ALL calculations and units. Round off final answers to TWO decimal

places.

6 Candidates may use non-programmable scientific calculators and drawing instruments.

7. The value of gravitational force should be taken as 10 m/s2. 8. All dimensions are in millimetres, unless stated otherwise in the question. 9. Write neatly and legibly. 10. Use the criteria below to assist you in managing your time.

QUESTION CONTENT MARKS TIME 1 Multiple-choice questions 10 20 minutes 2 Safety 20 20 minutes 3 Tools and Equipment 20 20 minutes 4 Materials 20 20 minutes 5 Terminology 30 35 minutes 6 Joining Methods 25 30 minutes 7 Forces 25 35 minutes

TOTAL 150 180 minutes CINCINNATI DIVIDING HEAD TABLE FOR MILLING MACHINE

Hole circles Side 1 24 25 28 30 34 37 38 39 41 42 43 Side 2 46 47 49 51 53 54 57 58 59 62 66

Standard change gears

24 x 2 28 32 40 44 48 56 64 72 86 100 )(40 divisionsofnumbernwhere

nformulaIndexing

Mechanical Technology Grade 10 MDE JUNE 2015

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QUESTION 1: MULTIPLE-CHOICE Choose the correct answer from those indicated by A, B, C and D and write your choice next to the question number.

1.1 Which ONE of the following is an unsafe condition in a workshop? A

B C D

poor lighting not using safety glasses run in the workshop playing in the workshop

(1) 1.2 What is the tool used to turn a nut recessed 30 mm deep? A

B C D

flat wrench socket wrench ring key combination key

(1)

1.3 Which of the following is a ferrous metal? A

B C D

aluminum medium carbon steel zinc brass

(1) 1.4 Name the test done to determine the resistance to penetration? A

B C D

density test scrape test hardness test spark test

(1) 1.5 What is the function of the lead screw on the lathe? A

B C D

speed increase automatic feed to cut thread to support the work piece

(1)

Mechanical Technology Grade 10 MDE JUNE 2015

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1.6 The hacksaw teeth should..... A

B C D

up show down show forward show backwards show

(1) 1.7 Into how many divisions is the help scale / secondary scale of the outside

micrometer divided?

A

B C D

25 48 49 50

(1)

1.8 What force is represented in the figure below? F F A

B C D

thrust traction shear strength compressed power

(1)

1.9 An accident can be seen as..... A

B C D

controllable something that happens only at certain times something that is well planned something completely unplanned that happens

(1)

1.10 What is the primary purpose of the Occupational Health and Safety act? A

B C D

ensuring the safety of the employer ensuring the safety of the employee ensuring that all machines are in good working condition ensuring that the employee is obedient to the employee

(1)

TOTAL QUESTION 1: [10]

Mechanical Technology Grade 10 MDE JUNE 2015

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QUESTION 2: TRUE OR FALSE Which of the following statements are true or false? Write the question number and

answer in your answer book.

2.1 Files can sometimes be used without handles. (1) 2.2 Low-carbon steel has a carbon content of 0, 25 - 0, 55%. (1) 2.3 The colour blue indicates drinking water pipes (1) 2.4 Wearing loose-fitting clothing is acceptable when working on the lathe (1) 2.5 A scribe is used to draw lines on steel. (1) 2.6 Non-ferrous metals are those metals which contain iron. (1) 2.7 An engine block is made of lead. (1) 2.8 One welds without a helmet, because it is a waste of time (1) 2.9 Ventilation is very important in a mechanical technology workshop. (1) 2.10 An outside micrometer is used to measure the length of a work piece (1)

TOTAL QUESTION 2: [10] QUESTION 3: SAFETY AND TOOLS 3.1 Name FIVE safety precautions to be observed when using a grinding

machine.

(5) 3.2 In a workshop different colours are used as codes. Explain the meaning of

the following colours in the workshop.

3.2.1 Green (2) 3.2.2 Orange (2) 3.2.3 Red (2) 3.3 There are THREE factors that must be remembered when handling tools,

name the THREE factors.

(3) 3.4 List FOUR different spanners that are used in a mechanical centre. (4)

Mechanical Technology Grade 10 MDE JUNE 2015

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3.5 There are different types of pliers that can be used in a mechanical

technology centre, name only FOUR.

(4) 3.6 Label the Vernier caliper shown in FIGURE 3.1 according to the letters A-I (9)

FIGURE 3.1 3.7 Provide the reading of the outside micrometer in FIGURE 3.2 (5)

FIGURE 3.2

3.8 Name four file profiles. (4)

TOTAL QUESTION 3: [40]

Mechanical Technology Grade 10 MDE JUNE 2015

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QUESTION 4: MATERIALS 4.1 What do you understand by the term alloy? (3) 4.2 Name the THREE groups of carbon steel and mention the percentage

carbon in each.

(6) 4.3 Match column A with column B

BV. 2 C

(5) Column A Column B

1. thermo setting plastics A. the lightest of all common metals

2. Aluminium B. excellent conductor of heat and electricity

3. thermo plastics C. after it has set, it cannot be re-heated to be made soft again

4. copper D. corrosion resistant. 5. zinc E. can be reheated and thus

formed again several times

4.4 One can identify metals in several ways, name FIVE ways. (5) 4.5 State ONE use of PVC regarding its isolation ability. (1)

TOTAL QUESTION 4: [20]

Mechanical Technology Grade 10 MDE JUNE 2015

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D B

C

A

E

F

G

H

QUESTION 5: TERMINOLOGY 5.1 Label the bench grinder FIGURE 5.1 according to the letters A-H (8)

FIGURE 5.1

5.2 Label the lathe in FIGURE 5.2 according to the letters A-J (10) A B C D E J F G I H

FIGURE 5.2

Mechanical Technology Grade 10 MDE JUNE 2015

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5.3 Name the TWO main types of cutters used in milling machines (2)

TOTAL QUESTION 5: [20] QUESTION 6: JOINING METHODS 6.1 Explain what is meant by semi-permanent joining methods. (3) 6.2 Identify the joints in FIGURES 6.1 and 6.2. 6.2.1

FIGURE 6.1

(1) 6.2.1

FIGURE 6.2

(1) 6.3 Two pieces of steel plate, each 25 mm thick, must be put together by means

of a double row-lap joint.

6.3.1 Calculate the bolt diameter (D). hint; diameter = 6.05 √ (3) 6.3.2 Calculate the pitch (P). hint; pitch = 3 x D (3) 6.4 Name THREE types of rivets. (3) 6.5 Determine the dimensions of a taper key to secure a pulley to a 60 mm

diameter shaft.

6.5.1 Width of the key (W) hint; W = D / 4 (2) 6.5.2 Thickness of key (T) hint; T = D / 6 (2) 6.5.3 length of key (L) hint; L = 1.5 x D (2)

TOTAL QUESTION 6: [20]

Mechanical Technology Grade 10 MDE JUNE 2015

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QUESTION 7 FORCES 7.1 Two pieces of rope are fixed to a nail. A piece of string is pulling in an easterly

direction with a force of 60 N. The other piece of string is pulling in a north easterly direction 60 with a force of 40 N. Determine the magnitude and direction of the resultant. Prove your answer by drawing the forces diagram and formulate your answer in a sentence.

(5)

7.2 A compressive force of 30 kN is exerted onto a round bar with a diameter of

15 mm. Calculate the stress in the bar.

hint: area =

stress=

(5)

7.3 Calculate the total moments caused by the forces in the following diagram.

Draw the diagram and do the calculation. 5,5 m 8,2 m 6 m 1750 N 2500 N

(4)

7.4 FIGURE 7.1 shows a single force of 160 N acting in a direction 35° north from

east. Determine by means of calculations the magnitudes and the directions of the horizontal and vertical components. 160 N 35° ---------------------------

FIGURE 7.1

(6)

TOTAL QUESTION 7 [20] GRAND TOTAL [150]

MARKS: 150

This memorandum consists of 8 pages.

MECHANICAL TECHOLOGY

MEMO

JUNE 2015

NATIONAL

SENIOR CERTIFICATE

GRADE 10

2 QUESTION 1: MULTIPLE QUESTION 1.1 A 9 (1) 1.2 B 9 (1) 1.3 B 9 (1) 1.4 A 9 (1) 1.5 C 9 (1) 1.6 C 9 (1) 1.7 C 9 (1) 1.8 B 9 (1) 1.9 D 9 (1) 1.10 B 9 (1)

TOTAL QUESTION 1 [10]

QUESTION 2 2.1 FALSE9 (1) 2.2 FALSE9 (1) 2.3 TRUE9 (1) 2.4 FALSE9 (1) 2.5 TRUE9 (1) 2.6 FALSE9 (1) 2.7 FALSE9 (1) 2.8 FALSE9 (1) 2.9 TRUE9 (1) 2.10 FALSE9 (1) TOTAL QUESTION 2 [10]

3 QUESTION 3: SAFETY AND TOOLS

3.1 Drill machine

x Choose the correctly sharpened drill for the type of work you need to

do and the material you are about to drill. 9 x Do not leave the key in the chuck when you are not at the machine. 9 x Never leave the machine running if unattended. 9 x Clamp the workpiece securely to the table and do not hold it by hand.

9 x Never attempt to stop the workpiece by hand if it slips from the clamp.

9 x Do not force a drill into the workpiece. 9 x Use a brush or wooden rod to remove chips from the drill. 9 x When reaching around a revolving drill, be careful that you clothe do

not get caught in the drill or drill chuck. 9 Any 5x1

(5) 3.2 Workshop different colours 3.2.1 Green

x The location of first-aid equipment9 x Emergency exits and safety areas9 x Information signs9 x Starting devices on electrical equipment9 x Miscellaneous safety conditions 9 Any 2x1

(2) 3.2.2 Orange

x electrical switchgear9 x electrical services9 x exposed and rotating machine parts9 Any 2x1

(2) 3.2.3 Red

x danger9 x fire protection9 x stopping devices9 Any 2x1

(2) 3.3 Handling tools

x use tools correctly9 x do not overload a tool9 x inspect tool for deficiencies before you use them9

(3) 3.4 Different spanners

x open-ended spanners9 x ring spanners9 x combination spanners9 x socket spanners9

(4)

4 3.5 Different pliers

x combination pliers9 x diagonal pliers9 x long-nose pliers9 x water pump pliers9 x vice-grip pliers9 x circlip pliers 9 Any 4x1

(4) 3.6 Vernier

A) inside measuring9 B) lock9 C) fixed scale9 D) depth measuring9 E) beam9 F) Vernier scale9 G) Sliding jaw9 H) Outside measuring9 I) Fixed jaw9

(9) 3.7 Outside micrometre reading

21 9+ 0 9+ 0,389 = 21,38 mm99

(5) 3.8 File profiles

x Flat files9 x Square files9 x Round files9 x Half-round files9 x Three-round files9 x Knife-edge files9 Any 4x1

(4) TOTAAL QUESTION 3 [40]

QUESTION 4 4.1 Alloys:

x Are the result of different non-ferrous metals having been melted together 9

x Lower the melting point9 x Increase the resistance to corrosion and rust9 x Change the colour and structure of the metal9 x Mat also reduce the cost of a metal9 Any 3x1

(3)

4.2 Carbon steel and percentage:

Low-carbon steel: 9 0,15 – 0,3 % 9 Medium carbon steel: 9 0,3 – 0,75 % 9 High-carbon steel : 9 0,75 – 1,5% 9

(6)

5 4.3 Column A / Column B

1. C 9 2. A 9 3. E 9 4. B 9 5. D 9

(5) 4.4 Identify metals:

x Hardness test 9 x Density test 9 x Fracture test 9 x Magnetic test 9 x Visual test 9 x Scratch test9 x Spark test9 x File test9 x Sound test9 x Machinability test9 Any 5x1

(5) 4.5 Use for PVC

x It is a tough material and can be purchased as a hard or flexible material. It is commonly used for insulating electrical cables. 9

(1) TOTAL QUESTION 4 [20] QUESTION 5 5.1 Bench grinder FIGURE 5.1

A) Grinding wheel 9 B) Wheel guard 9 C) Head 9 D) Perspex shield 9 E) Maximum gap 3 mm 9 F) Tool rest 9 G) On/off switch 9 H) Stand 9

(8) 5.2 Lathe FIGURE 5.2

A) Chuck 9 B) Tool post 9 C) Compound slide 9 D) Tailstock 9 E) Hand wheel9 F) Saddle/ carriage 9 G) Lead screw 9 H) Power feed control 9 I) Carriage hand wheel 9 J) Cross feed handle 9

(10) 5.3 Main types of cutters

x Arbor cutters 9 x Shank cutters 9

(2) TOTAL QUESTION 5 20

6 QUESTION 6 6.1 Semi- permanent joining methods

x Methods to join different objects together, securely but not necessarily permanently. 999

(3) 6.2 Identify the joints in FIGURE 6.1 AND 6.2 6.2.1 lap joints 9 (1) 6.2.2 Butt joints 9 (1) 6.3 Two pieces of steel plate: 6.3.1 Bolt diameter

6.05 √ 9 = 6.05 √ 9 = 30,25 mm 9

(3) 6.3.2 Pitch

3 x D 9 = 3 X 30,25 mm 9 = 90,75 mm 9

(3) 6.4 Types of rivets

x Blind rivets 9 x Standard open type 9 x Sealed type 9 x Grooved type9 x Peel type9 Any 3x1

(3) 6.5 Dimensions of a taper key 6.5.1 Width of the key

60 / 4 9 = 15 mm 9

(2) 6.5.2 Thickness of key

60 / 6 9 = 10 mm 9

(2) 6.5.3 Length of key

1.5 x 60 9 = 90 mm 9

(2) TOTAL QUESTION 6 (20)

7 QUESTION 7 7.1 FORCES (5) Resultant force is 84 N at 26°99 7.2 STRESS

MPa778,169StressPa9,169779286Stress

10767,11030Stress

arealoadStress

m10767,1Area4

)015,0(Area

4dArea

4

3

24

2

2

uu

u

uS

uS

�

�

(5) 7.3 Moments Moment at A

Nm9625A17505,5A

u

(2) Moment at B

� �Nm34250B

25002,85,5B

u�

(3) 7.4 Vertical component

N772,91Y35sin160Y 0

Horizontal component

N06,131X35cos160X 0

(6) TOTAL QUESTION 7 (20) GRAND TOTAL [150]

84 N9 40N9

60N9

9 9 9 9 9

9 9

99 9

99 9

99 9