Summer Exams 2022 LC 5th

Question 1

Explain term Synthetic Fibre

Answer 1

Chemically man-made fibre

Question 2

Name 2 composite materials and their constiuents

Answer 2

Concrete (water, cement, aggregate)

Plywood (thin layers of wood glued together)

Question 3

Explain ‘alloy’ and give an advantage

Answer 3

Mixture of 2 or more metals

It is stronger & more durable

Question 4

Name the metals to produce following: Bronze & Solder

Answer 4

Bronze: Copper + Tin
Solder: Lead + Tin

Question 5

Describe ‘resistance to impact’ as material property

Answer 5

The ability of a material to cope with shock load. It is a indicator of material toughness.

Question 6

Outline an impact test to compare materials for the manufacture of bicycle helmets

Answer 6

Izod Impact Test

Question 7

Briefly outline what is meant by Synthetic materials & Natural materials

Answer 7

Synthetic materials are chemically made by man-kind

Natural materials is made by plants or animals (naturally)

Question 8

Complete missing information table:
Body Part: Seat
Material Classification: Fabric
Material: ?

Answer 8

Material: Polyester

Question 9

Complete missing information table:
Body Part: Tyre
Material Classification: ?
Material: Steel-enforced rubber

Answer 9

Material Classification: Rubber

Question 10

Complete missing information table:
Body Part: Headlight Lens
Material Classification: Ceramic
Material: ?

Answer 10

Material: Polycarbonate

Question 11

Explain abbreviation: PET

Answer 11

Polyethylene Terephthalate

Question 12

Outline 3 disadvantages of extensive use of PET bottles

Answer 12

Pollution
Not Biodegradable
Becomes Toxic in presence of Heat

Question 13

Outline one way in which plastic bottles are designed to maximise their strength

Answer 13

Use a strong a material like PET

Question 14

Explain with examples, each of following:
Mass Production
Batch Production

Answer 14

Mass Production: Produced in large quantities, usually by machinery. Example: plastic bottles
Batch Production: Producing many identical products simultaneously. Example: clothes

Question 15

Differentiate between following forces:
Tension
Torsion
Compression

Answer 15

Tension: stretching of material
Torsion: twisting of material
Compression: squeezing/pushing of material

Question 16

Describe with examples, how metal alloys and manufactured boards can increase the strength of the final material

Answer 16

Metal alloys improve the hardness of material while manufactured boards increases its strength

Question 17

Explain abbreviation: CNC

Answer 17

Computerized Numerical Control

Question 18

Outline 2 reasons why CNC is used in manufacturing of products

Answer 18

They’re cost effective

Reduces errors in manufacturing process

Question 19

Describe what is meant by smart material

Answer 19

Smart materials are materials that are manipulated to respond in a controllable and reversible way

Question 20

Suggest 2 uses of electrochromic glass in every day life

Answer 20

Skylights

Classroom settings

Question 21

Discuss why it is important to consider how a product is disposed of once it reaches its end-of-life

Answer 21

Depending on the product, its material or any substances it contains must go to an appropriate place as it can be toxic or bring about harm

Question 22

Briefly outline two options available when disposing of a product such as a dog wheelchair

Answer 22

Incineration
Scrap
Landfills

Question 23

Describe what is meant by ‘veneer’ when referring to materials

Answer 23

A thin slice of more expensive woods that is often applied to manufactured boards to improve appearance and give an impression of high cost

Question 24

Briefly outline 2 reasons why manufactured boards are often used instead of solid wood in furniture production

Answer 24

Cheap

Come in big sheets

Question 25

Outline 3 properties of Plywood that make it a suitable material for manufacturing of hoverboard or skateboard decks

Answer 25

``` Strength of material Can be bent to shape Cuts to shape easily Finishes well Flexible ```

Question 26

Describe a simple material test which could be used to determine if a given material is suitable for use in skateboard wheels

Answer 26

Load a material test sample against a rotating wheel and then deposit sand of controlled grit size, composition and flow rate between them

Question 27

Select a suitable material for the anti slip surface on the pedal pads. Justify your answer.

Answer 27

Rubber It is a reasonably soft material that wears well giving good grip.

Question 28

Suggest 2 alternatives materials for takeaway coffee cups which can be recycled or will biodegrade

Answer 28

Paper Cardboard Glass PLA-lined cups

Question 29

Describe two advantages of incineration as a method of disposing of expanded polystyrene

Answer 29

Saves sending to landfill Waste disposal for long life material Acts as a fuel in for incineration

Question 30

State 2 reasons for using steel tubing in the construction of racing cars

Answer 30

Tubing reduces weight Reasonably cost effective High strength-to-weight ratio

Question 31

Outline some benefits to consumers & environment of increasing use of electric cars

Answer 31

Expect reduced running costs Cleaner air Less noise pollution Less burning of fossil fuels Smoother & quieter driving experience

Question 32

Outline with examples, 2 advantages of using composite materials

Answer 32

A composite material is a combination of 2 or more chemically distinct materials with improved properties 1. Plastic laminates provide a waterproof layer on chipboard for kitchen counters 2. GRP is lightweight and strong

Question 33

Suggest 2 reasons for extensive use of glass in manufacture of Luas trams

Answer 33

Visibility for passengers Security of passengers Light weight

Question 34

Describe main properties of Thermosetting plastics. Give example(s).

Answer 34

Thermosetting can be set only once. They're hard and have high melting point. Example: Bakelite

Question 35

Describe main properties of Ferrous Metals. Give example(s)

Answer 35

Ferrous metal contain iron. Example: Steels are magnetic, malleable and ductile

Question 36

Describe main properties of Softwoods. Give example(s)

Answer 36

Softwoods are evergreen, soft and mature quickly | Example: pine

Question 37

Outline 2 potential hazards when using adhesives to bond materials

Answer 37

Adhesives can produce dangerous fumes, ventilation is needed Care must be taken to not bond skin. Suitable adhesive must be selected to ensure good adhesion.

Question 38

Describe key features of following materials & give example(s): Thermoplastics

Answer 38

Will mold more than once, recyclable. | Example: Polyethylene & PVC

Question 39

Describe key features of following materials & give example(s): Smart materials

Answer 39

Materials that respond to an external input | Example: memory wire, polymorph

Question 40

Describe key features of following materials & give example(s): Manufactured boards

Answer 40

Wooden products generally produced from by-products of cutting timber Example: Plywood, MDF

Question 41

Outline main safety hazards on following processing techniques: Cutting MDF on a circular saw

Answer 41

Generation of dust Fine particles Need for extraction

Question 42

Outline main safety hazards on following processing techniques: Joining plastic materials using adhesives

Answer 42

Fumes from solvent adhesives | Flammability

Question 43

Outline main safety hazards on following processing techniques: Cutting metal on centre lathe

Answer 43

Sharp Hot metal chips Need eye protection

Question 44

Select an impact-resistant material for the door wedge. Justify your answer.

Answer 44

Polypropylene - can be injection moulded Resistant to impact Colorful

Question 45

Discuss the environmental impact of producing the toy car using vacuum forming techniques

Answer 45

Production of plastic materials from oil: extraction, energy use, transport etc Electrical energy used in process Recyclable plastic material

Question 46

Describe with the aid of detailed sketches, the process of vacuum forming?

Answer 46

This method is used to produce hollow shapes in plastic sheets. A shaped mould is produced, usually in wood, and placed in the machine. The sheet of plastic is placed over the mould & clamped. The sheet of plastic is heated until soft and drawn onto the mould. Vacuum created -> air removed from area of mould. The plastic sheet will take shape of the mould. (machine turned off, mould removed and trimmed) Practice drawing it yourself!

Question 47

Describe with the aid of detailed sketches, the process of injection moulding?

Answer 47

Practice drawing it yourself!

Question 48

Describe with the aid of detailed sketches, the process of extrusion moulding?

Answer 48

Practice drawing it yourself!

Question 49

Describe, using annotated sketches, a suitable production method for the plastic housing

Answer 49

Injection moulding: plastic pellets are loaded from the hopper through the heated chamber. It is pushed into the housing shaped mould by the rotating screw ALSO PROVIDE A SKETCH!

Question 50

Explain, using annotated sketches, the process of vacuum forming

Answer 50

This method is used to produce hollow shapes in plastic sheets. A shaped mould is produced, usually in wood, and placed in the machine. The sheet of plastic is placed over the mould & clamped. The sheet of plastic is heated until soft and drawn onto the mould. Vacuum created -> air removed from area of mould. The plastic sheet will take shape of the mould. (machine turned off, mould removed and trimmed) Practice drawing it yourself!

Question 51

Describe, using annotated sketches a method of commercially manufacturing the front cover of this device.

Answer 51

Injection moulding: A hollow split mould is machined to the shape of casing. Plastic granules are held in hopper and fed into machine where heated and pushed into the mould cavity by screw/ram mechanism. The molten plastic fills the mould under heat and pressure. It sets quickly. (Mould is split -> casings removed -> trimmed) Practice drawing it yourself!