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Energy Transfer
Noadswood Science, 2012
+Energy & Electricity
To revise energy transfers and work out current and charge in an electric circuit
Monday, April 10, 2023
+Energy
What is energy?
What types of energy are there?
+Energy
Energy is the ability to ‘do some work’ - everything that happens needs energy (e.g. heating; cooking; lighting; movement of vehicles; and keeping us alive)!
Energy cannot be created or destroyed, only transferred from place to place in a variety of ways
+Types Of Energy
Electrical energy - a current in a circuit etc… Light energy - from the sun; a light bulb etc… Sound energy - from a loudspeaker; a drum etc… Kinetic (movement) energy - anything which moves! Nuclear energy - transferred during a nuclear reaction Thermal (heat) energy - transferred from hot objects to
colder ones Radiant heat (infra red) energy - transferred as
electromagnetic radiation by hot objects Gravitational potential energy - possessed by anything
with the ability to fall Elastic potential energy - stretched springs; elastic and
rubber bands etc… Chemical energy - possessed by food; fuels; batteries
etc…
+Energy Transfer
Different types of energy can be transferred from one type to another
Energy transfer diagrams show each type of energy, whether it is stored or not, and the processes taking place as it is transferred
+Energy Transfer
Different types of energy can be transferred from one type to another
Energy transfer diagrams show each type of energy, whether it is stored or not, and the processes taking place as it is transferred
+Sankey Diagrams
Sankey diagrams show the relative amounts of each type of energy
They summarise all the energy transfers taking place in a process – the thicker the line or arrow, the greater the amount of energy involved
Sankey diagram of a light bulb
+Wasted
Energy can be 'wasted' during energy transfers
Energy cannot be created or destroyed, only transferred from one form to another
Energy that is ‘wasted’ (e.g. heat energy from an electrical lamp) does not disappear – instead it is transferred to the surroundings, spreading out so much that it becomes difficult to do anything useful with
+Lamps - Ordinary
Ordinary electric lamps contain a thin metal filament that glows when electricity passes through it – however, most of the electrical energy is transferred as heat energy instead of light energy: -
+Lamps – Energy Saving
Modern energy-saving lamps work in a different way – they transfer a greater proportion of electrical energy as light energy: -