Extracts from this document...

Introduction

MATERIALS Materials (definition) = Substances that an object is made of Materials are used to make many non-living things. Eg: Wood (chair / doll / book) Rubber (eraser / tyre) Metals (ornaments / metal ruler) Leather (wallet / shoe) Rocks (bricks) More than one material can be Glass (spectacles / mugs) used to make a single object Cotton (shirt / skirt) (eg: bulb <-- metal + glass) Plastic (toys / outer covering of pen) (eg: shoe <-- rubber+metal+leather) Copper (electric wire) Clay (brick/ flower pots) > Where do we get these materials? a) Man made - plastic, nylon, Styrofoam b) Ground - rocks, glass, metals(iron/copper), sand, clay c) Plants - wood, cotton, rubber) d) Animals (leather, wool, silk We must Reduce, Reuse & Recycle materials > Why must we study about materials? - to know their characteristics --> choose the right material for the manufacturing - When you choose materials to make an object, you must know * The properties of the material * Uses of the object Some characteristics (properties) of materials: - Shape/size/colour/shiny/taste - hard / soft (texture) - strong / weak (strength) - heavy / light - flexible / stiff - sink / float in water - water proof - degree of transparency to light - durable (not easy to break) - conduct heat - heat resistant - doesn't rust - malleable (easy to change shape by bending - copper) - magnetic/nonmagnetic - conduct electricity or not - soluability Strength: Key/gold > Melamine > Wood > Rubber (gold is stronger than melamine) ...read more.

Middle

Item Material used Why we use this material? Car tyre Rubber - Water proof & grip on road (Not for moving faster) - Durable Duckie Rubber Flexible & not absorb water Nail Iron Hard & strong Door Wood Strong but light Rain coat Plastic Light & not absorb water Aquarium Glass Hard & not allow water & can see through T Shirt Cotton Soft & light Roof Ceramic Hard & water proof Table Plastic/metal/wood Strong Water hose Rubber Flexible & water proof Window pane Glass See through & strong wall concrete Strong Sinker for fishing rod metal Sinkable (density higher than water) Safety boots for electrician Rubber (NOT copper) Insulator of electricity Fire alarm Glass Seethrough & easily breakable Pot holder Cotton & Batting Do not conduct heat & donot melt CLASSIFICATION OF MATERIALS WHAT IS CLASSIFICATION? Grouping of objects into sets according to one or more common properties. HOW DO WE CLASSIFY? Classified using their properties (similarities/differences) - colour - flexibility - hardness - strength - degree of transparency to light - magnetic property - thermal property - electrical property - density - boiling point & melting point - malleable (can change shape without breaking) - ductile (capable of being hammered out thin) WHY CLASSIFY? a) Get the things organized to find them easily <-- It allows you to see things in an orderly way. b) Easier to study To show similarities and differences among different things <-- You cannot study everything around you. So, by knowing the group, you'll get to know the characteristics c) ...read more.

Conclusion

> Viscosity Def - Ability of a liquid to flow (describes how easily or how difficult the liquid flows) > Transparency to light Def - Ability of a substance to aloow light to pass through it a) Transparent - Materials that allow most light to pass through (clearly see through) b) Translucent - Material that allow some light to pass through (cannot clearly see through) c) Opaque - Materials that do not allow light to pass through (cannot see through) Material Property Uses a) transparent Example: * Glass Allows most light to pass through * Spectacle lenses * windscreens b) translucent Example: * Frosted glass Allows some light to pass through * Bathroom windows c) Opaque Example: * Wood Metal Doesn't allow most light to pass through * Wall * doors > Magnetic property a) Magnetic b) Non magnetic Material Property Uses a) magnetic Example: * Iron * steel Can be attracted to a magnet * Buttons to keep handbags closed * Door stoppers * Magnetic notice boards b) Non magnetic Example * Paper * rubber SOME OTHER WAYS TO CLASSIFY MATERIALS Classification 1 - Once alive & never alive Classification 2 - Natural & Man-made * Natural - crude oil, carbon, iron, copper, wood, rubber * Man made (synthetic) - these are made from different natural material that are processed to produce new man-made materials Eg: petrol & plastic (made from crude oil), glass, steel Classification 3 - Metals & Non-metals * Non metals - plastics, fibres, glass, ceremic * Metals - iron titanium, aluminium, gold, zinc, copper, lead Some experiments: Sec 1 Page 1 P6.2 Page 6 P6.2 Page 18 ...read more.

This student written piece of work is one of many that can be found in our AS and A Level Design and Technology section.