energy and electricity
- 1. 11/22/14 EEnneerrggyy aanndd EElleeccttrriicciittyy W Richards The Weald School
- 2. TThhee 99 ttyyppeess ooff eenneerrggyy 11/22/14 Type 3 example sources Heat Kinetic (movement) Nuclear Sound Light Chemical Electrical Gravitational potential Elastic potential
- 3. EEnneerrggyy cchhaannggeess 11/22/14 To describe an energy change for a light bulb we need to do 3 steps: 1) Write down the starting energy: 3) Write down what energy types 2) Draw an arrow are given out: Electricity Light + heat What are the energy changes for the following…? 1) An electric fire 2) A rock about to drop 3) An arrow about to be fired
- 4. EElleeccttrriiccaall EEnneerrggyy 11/22/14 Consider a simple circuit: 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. Words – electrical (x2), light, chemical
- 5. EElleeccttrriiccaall EEnneerrggyy 11/22/14 Energy Hi. I’m Ernie Electron and I’m going to show you how I get energy around a circuit.
- 6. EElleeccttrriiccaall EEnneerrggyy 11/22/14 Energy Hi. I’m Ernie Electron and I’m going to show you how I get energy around a circuit.
- 7. EElleeccttrriiccaall EEnneerrggyy 11/22/14 Hi. I’m Ernie Electron and I’m going to show you how I get energy around a circuit. Energy
- 8. FFuueellss 11/22/14 A “fuel” is something that can be burned to release heat and light energy. The main examples are: Coal, oil and gas are called “fossil fuels”. In other words, they were made from fossils.
- 16. WWhhaatt ddooeess eeaacchh ppaarrtt ddoo?? 11/22/14 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
- 17. 11/EEnneerrggyy TTrraannssffeerr ddiiaaggrraammss 22/14 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 100 J/s electrical energy 20 J/s light energy 80 J/s heat energy (given to the surroundings)
- 18. EExxaammppllee qquueessttiioonnss 11/22/14 Consider a kettle: Sound energy 1) Work out each energy value. 2) What is the kettle’s efficiency? Wasted heat Heat to water 2000 J/s electrical energy Consider a computer: 150 J/s electrical energy 10 J/s wasted sound 20 J/s wasted heat Useful light and sound 1) How much energy is converted into useful energy? 2) What is the computer’s efficiency?