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Energy and Electricity. The 9 types of energy. Energy changes. 1) Write down the starting energy:. 3) Write down what energy types are given out:. Electricity Light + heat. 2) Draw an arrow. To describe an energy change for a light bulb we need to do 3 steps:.
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Energy changes 1) Write down the starting energy: 3) Write down what energy types are given out: Electricity Light + heat 2) Draw an arrow To describe an energy change for a light bulb we need to do 3 steps: • What are the energy changes for the following…? • An electric fire • A rock about to drop • An arrow about to be fired
Electrical Energy The job of the battery is to convert ______ energy into _________ energy… The job of the bulb is to convert the _________ energy it receives from the battery into ______ energy. Consider a simple circuit: Words – electrical (x2), light, chemical
Electrical Energy Energy Hi. I’m Ernie Electron and I’m going to show you how I get energy around a circuit.
Electrical Energy Energy Hi. I’m Ernie Electron and I’m going to show you how I get energy around a circuit.
Electrical Energy Energy Hi. I’m Ernie Electron and I’m going to show you how I get energy around a circuit.
Fuels Coal, oil and gas are called “fossil fuels”. In other words, they were made from fossils. A “fuel” is something that can be burned to release heat and light energy. The main examples are:
Renewable energy sources Wind Hydro-electric Wave Tidal Geothermal Biomass
Power stations Transformer Boiler Turbine Cooling tower Generator
What does each part do? The boiler is where the fuel is burnt to boil water The steam from the boiler is used to turn a turbine The turbine is connected to the generator, which acts like a dynamo – it generates electricity out of movement The steam is cooled down and turned back into water in the cooling tower
Energy Transfer diagrams Consider a light bulb. Let’s say that the bulb runs on 100 watts (100 joules per second) and transfers 20 joules per second into light and the rest into heat. Draw this as a diagram: “Input” energy “Output” energy 20 J/s light energy 100 J/s electrical energy 80 J/s heat energy (given to the surroundings)
Example questions Consider a kettle: Consider a computer: 2000 J/s electrical energy 150 J/s electrical energy 20 J/s wasted heat Wasted heat Heat to water Useful light and sound 10 J/s wasted sound Sound energy • Work out each energy value. • What is the kettle’s efficiency? • How much energy is converted into useful energy? • What is the computer’s efficiency?