Leaving Cert Technology 2012

In the promotion of alternative sources of energy in Ireland, the harvesting of wind energy has been prioritised.  Outline the main advantages of a wind-powered energy system.Suitable for Irish climate/exposed areas,  Reduce reliance on imported fossil fuels,  Less pollution,  Can be harvested on land/at sea etc.

Corrugated cardboard is a commonly used material in the packaging industry.  Describe one advantage and one disadvantage of using cardboard rather than expanded polystyrene in the packaging of electrical items.Advantage: Made from renewable wood, more environmentally friendly than polystyrene etc.  Disadvantage: Will not mould as effectively as polystyrene, not waterproof etc. Give one reason for the corrugation of cardboard.Considerably adds to strength and rigidity, better impact protection etc. 

A variety of materials is used in the manufacture of modern boats. Name a suitable material to be used for each boat-part listed and outline a property of each material. Part            Material                               Property  Sail       Nylon/Canvas etc.        Lightweight, colourful, strong, will not tear easily etc. Mast      Aluminium                   Strong and lightweight in tubes  Hull       Fibre glass                  Impact resistant, moulds in one piece, waterproof etc.

The forces acting on a structure can be described in terms of tension, compression, shear and torsion. Briefly explain any three of these terms.  Tension - pulling or stretching force  Compression - squeezing force.  Shear - cutting force  Torsion - twisting force etc.

Distinguish between potential energy and kinetic energy.  Potential energy due to the position of an object.  Kinetic is energy due to the motion of an object. Identify an energy conversion that takes place in:  (i) A 12V car battery: Chemical to electrical.  (ii) An electric motor: Electrical to kinetic/mechanical etc. 

Supermarkets use automated point of sale (POS) equipment or ‘checkouts’ with barcode readers.  Outline two functions of a barcode system.     A quick and efficient way of processing and totalling information such as prices.   An effective method of instant stock monitoring and control etc.

Bearings are commonly used in machines and vehicles.    (i) Outline two reasons for using bearing systems.    Reduction of friction,  Smooth motion,  Less wear,  Reduction in noise and heat etc.     ii) The generation of heat due to friction needs to be minimised in bearings. Name two lubrication materials used to minimise heat.  Oil,  Grease,  Dry graphite etc. 

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