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Materials and their Properties PowerPoint Presentation
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Materials and their Properties

Materials and their Properties

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Materials and their Properties

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Presentation Transcript

  1. Materials and their Properties

  2. Comparing Materials • Materials have certain PROPERTIES which make them USEFUL We need to be able to describe and compare the properties of a material and say why its used for a job. We use certain materials for certain jobs…

  3. strong Steel Bridge Plastic container

  4. hard Metal hammer head Diamond ring

  5. flexible Leather belt Fishing rod

  6. Rigid Metal scaffolding ladder

  7. transparent window

  8. absorbent Paper towels/tissues towelling

  9. stretchy Stretch fabric Elastic band

  10. squashy springs

  11. Conductors and Insulators of Heat • Some Materials let Heat pass through them Easily • These materials are called THERMAL CONDUCTORS • METALS are good THERMAL CONDUCTORS • Because heat passes through them quickly – metal normally feelsCOLD

  12. Some Materials Do Not let Heat pass through them 1) Materials that do not let heat pass through them are called THERMAL INSULATORS. Oven glove Wooden handle thermals

  13. 2) Plastic, cork, wood and fabrics are good THERMAL INSULATORS 3) Thermal insulators are good for keeping heat OUT as well as IN Fridge – keeps heat out Polystyrene cup – keeps heat in Thermos Does both

  14. A good insulator = a poor conductor

  15. Heat travels from a warmer material to a colder one

  16. Conductors and Insulators of Electricity • Conductors let electricity flow through them 1)Materials that can carry electricity are called conductors – they conduct electricity 2) Metals like copper, iron, steel and aluminium are all good conductors.

  17. Insulators do not let electricity flow through them • Materials that can not carry electricity are called insulators – they do not conduct electricity • Wood, plastic, glass and rubber are all insulators.

  18. Insulators and Conductors both have important Uses Wires are coated in plastic – electricity cant flow through it so you don’t get a shock if you touch it Copper wire allows electricity to flow through A plug has metal pins – conduct electricity, insulated flex and a plastic cover to hold

  19. Electricity can be dangerous You shouldn’t tough anything electrical with wet hands – and that includes switches. Electricity can be conducted through sweat (salty water) to your body, giving you and electric shock Remember – water conducts electricity