Which materials are widely used in engineering? What is meant by recycling? How does recycling affect engineering design? Which materials are widely used in engineering? What is meant by recycling? How does recycling affect engineering design?

 Look at page 14  Do 1.1.  Complete 2.a  Look at page 14  Do 1.1.  Complete 2.a

 Look at the meaning of the following words:  magnetism = force of attraction  galvanized = coated with zinc (Zn) to prevent rusting  recyclable = can be recycled  chromium = (Cr) and nickel (Ni) = metals added to steel to make stainless steel  traces = small quantities  scarcity = limited availability /rarity  insulation = both electrical insulation and thermal insulation  Look at the meaning of the following words:  magnetism = force of attraction  galvanized = coated with zinc (Zn) to prevent rusting  recyclable = can be recycled  chromium = (Cr) and nickel (Ni) = metals added to steel to make stainless steel  traces = small quantities  scarcity = limited availability /rarity  insulation = both electrical insulation and thermal insulation

 wire = single strand of metal  scrap = waste material intended for recycling  alloy = a mixture of metals sometimes containing a non-metal, for example carbon (C) in steel  brass = an alloy of copper (Cu), zinc and, often lead (Pb) /led/  bronze = an alloy of copper and tin (Sn)  wire = single strand of metal  scrap = waste material intended for recycling  alloy = a mixture of metals sometimes containing a non-metal, for example carbon (C) in steel  brass = an alloy of copper (Cu), zinc and, often lead (Pb) /led/  bronze = an alloy of copper and tin (Sn)

 melting down = using heat to change the state of a substance from solid to liquid  energy-intensive = using a lot of energy  electrolysis = passing an electrical current through a liquid or solid in order to separate chemical compounds  ore = mineral from which metal is extracted  hardwood = timber from pine trees  melting down = using heat to change the state of a substance from solid to liquid  energy-intensive = using a lot of energy  electrolysis = passing an electrical current through a liquid or solid in order to separate chemical compounds  ore = mineral from which metal is extracted  hardwood = timber from pine trees

 softwood = timber from pine trees  ironmongery = collective term for small metal items commonly used in buildings, for example door handles, hingers, screws, nails.  Do exercise 2a  Do exercise 2c  Homework 3a, 3b, 3c, 3d  softwood = timber from pine trees  ironmongery = collective term for small metal items commonly used in buildings, for example door handles, hingers, screws, nails.  Do exercise 2a  Do exercise 2c  Homework 3a, 3b, 3c, 3d

 Putting materials into different categories/ types. Example: Metals - steal + copper  Putting materials into different categories/ types. Example: Metals - steal + copper

 Do 4 NOTE brakes are designed to slow down vehicles or moving parts. often they work through friction, by applying pressure to pads which are pressed against the sides of the disc, the inside of the drum, or directly against a wheel rim.  Do 4 NOTE brakes are designed to slow down vehicles or moving parts. often they work through friction, by applying pressure to pads which are pressed against the sides of the disc, the inside of the drum, or directly against a wheel rim.

Alternatives use systems that use electro magnetic force, systems that exploit the braking effects of engines or flywheels (via clutches and gearboxes), aerodynamic braking systems ( for example spoilers on aircraft, parachutes on dragsters), and reverse thrusters on jet engines. Brake discs are often made of ferrous metals (iron-base_ for example steel), or sometimes ceramic materials.

Examples of materials used to make pads include: compounds of advanced materials (cars), ferrous metals (trains), rubber (bicycles), ceramics (performance cars)

 Do task 5a. Note: Green refers to ecological issues Red refers to heat (red hot means very hot) A hot topic is a current important topic

Read the text and answer the questions in 5b Answers: 1. Because they use friction, which wastes energy as heat 2. They recover heat and use it to power the car 3. The ability to generate high levels of friction, and to resist the effects of friction and consequent heat Heat from the engine being absorbed by the chassis, which can damage sensitive parts such as electronic components and plastic parts