Y10 Graphics End of Year

physical properties of a material

ones that can be observed or measured without changing the composition of a material

absorbency, density, fusibility, electrical conductivity, thermal conductivity

physical properties: absorbency

the ability of a material to soak up a liquid

physical properties: density

the mass per unit volume - a measurement of the mass of a material and how much space it takes up. a more dense material will feel heavier for its size

physical properties: fusibility

the ability of a material to melt into a liquid or molten state when heated. normally associated with metals & polymers

physical properties: electrical conductivity

the ability to conduct electricity. metals are good conductors, while polymers are good insulators

physical properties: thermal conductivity

the ability to conduct heat. metals are good conductors, while polymers are good insulators

working/mechanical properties of a material

the material’s ability to resist certain external forces being applied to it

strength, hardness, toughness, malleability, ductility, elasticity

working/mechanical properties: strength

the ability to withstand force e.g. by resisting compression (squashing) or tension (stretching)

working/mechanical properties: hardness

the ability to resist abrasive wear

working/mechanical properties: toughness

the ability to withstand sudden stress or shocks

working/mechanical properties: malleability

the ability to permanently deform when worked without breaking. also known as plasticity

working/mechanical properties: ductility

the ability to be drawn out or stretched without breaking

working/mechanical properties: elasticity

the ability to bend and return to shape without breaking when subjected to a force

selection of materials or components: functionality

what the material is intended to do and how it performs for the user

selection of materials or components: aesthetics

how attractive/pleasing the material needs to be in a product in terms of form, colour, and texture

selection of materials or components: environmental factors

the energy consumption, pollution, and sustainability from the material’s initial sourcing and extraction, manufacture, use, and disposal

selection of materials or components: availability

materials need to be readily available in their raw form / as components

materials that are specialist, scarce, or difficult to source will have a higher cost. the use of stock materials will benefit designers and customers

selection of materials or components: cost

the cost of the raw material and processing, through to the manufacture of the product

heavily influenced by the scale of production

selection of materials or components: social factors

companies must consider social factors when selecting materials.

the needs of the people have high priority, for example the specific needs of children, disabled, or elderly

factors in a consumer society e.g. trends & fashions may be a factor

selection of materials or components: cultural factors

different faiths & beliefs may impact the development of products

this doesn’t just impact design - the origin of materials may also be important e.g. materials derived from animals need to be carefully considered

selection of materials or components: ethical factors

materials can be purchased from ethical sources e.g. wood that has been responsibly managed by the FSC or products endorsed by the fairtrade foundation (means workers haven’t been exploited)

why are standard/stock forms of materials helpful in selection of materials or components

makes the material more cost effective as it gives designers ready-made materials that can be incorporated into their designs

force definition

a load that has been applied, measured in newtons (N)

stress definition

produced as a load is applied to a material and may cause it to deform

tension

pulling force e.g. a rope

compression

force pressing on a material - being squashed

bending

forces at an angle to the material causing both tension & compression at the same time

neutral axis: the point between the tension and compression forces

torsion

twisting force, often along the length of a material

shear (force)

when two parallel forces that are out of alignment are acting against each other e.g. blades of scissors acting against each other to shear paper

static load

load that doesn’t move and is constant e.g. books sitting on a shelf

dynamic load

load that is unstable or moving, which tends to increase the force applied to the material e.g. someone walking over a footbridge

ecological issues associated with product design

deforestation = loss of wildlife & soil erosion

mining = changes to the landscape, loss of habitat, noise and vibration

farming = loss of habitat (as farmers expand into new areas to find good soil)

transportation of products = pollution (from fuel usage)

production of carbon (during manufacture)

use of finite raw materials

use of landfill = chemical leaks into the ground, poisoning wildlife & humans

ecolocical issues - sustainability

companies must consider sustainability of the manufacture, use, and disposal of their products

sustainable products reduce demand on non-renewable raw materials and energy sources, produce less waste, and reduce pollution

carbon footprint

the amount of CO2 emissions that is directly or indirectly attributed to an individual / company, including:

• extraction, transportation, processing and manufacture of products

• power consumption (e.g. electrical power)

• recycling & end-of-life disposal of products

• travel e.g. commuting, holidays etc

how to reduce carbon footprint

energy: efficient house insulation, low energy lighting, alternative energies, turn down heating

water: reduce water use, turn off taps

travel: low carbon vehicles or car sharing, minimise number of journeys

recycling: recycle used glass, plastics, and paper

offsetting: offset carbon emissions by a tree planting programme

up to

ecological issues 1 pg 100 (finished)