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Energy Transfer

Energy Transfer

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Energy Transfer

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  1. Energy Transfer Syllabus Title Page Lesson 01 Types of Energy Lesson 02 Energy Efficiency Lesson 03 Conduction and Convection Lesson 04 Radiation and Insulation Lesson 05 Insulating Homes

  2. Energy Energy

  3. Energy Transfers27/11/2014 Aim: • To define energy • To explain the purpose of a transducer and their role in the conservation of energy • To identify energy transfers Starter: in rough • Write down words / phrases about energy • Compare with your neighbour • Compare with your table • Agree a definition of energy and one of you write it down (can be more than one sentence)

  4. Energy Definition: • Energy is required to do anything (work) (e.g. heat up). • Energy is always conserved, it is never used up or destroyed it is transferred into another form (e.g. chemical to heat and light). • A transducer changes energy from one form to another (e.g. a match). Symbol: E Unit: J (joules) Analogy: • Energy is like money. • To do anything costs money. • Money is not used up but changes hands when you pay for something. HandoutDemo Burning Ethanol

  5. Types of energy • There are two groups of energy and nine types you need to learn • In rough write down what types of energy you can think of in 1 minute(think about the burning ethanol demo)

  6. Types of Energy ACTIVE (KINETIC) ENERGY STORED (POTENTIAL) ENERGY Electrical energy

  7. Types of Energy • _________ _______ (KE) are all types of movement energy. • _________ _______ (PE) are all types of stored energy. Kids Hate Learning GCSEEnergy Names

  8. On your white board write down the type of energy • Energy in a toffee • Energy in a running girl • Energy causing a light bulb to light • Energy given off by a stationary boy • Energy in music • Energy in a spring shot • Energy in a diver

  9. Energy Transfers Watch the demo (flour fire breathing) What energy transfers are occurring?

  10. Example Energy Transfers? electrical sound kinetic electrical light chemical electrical kinetic

  11. More Complicated Examples There can be more than one step gravitational potential kinetic electrical Energy can be transferred into more than one type electrical heat sound light

  12. Energy Circus • Around the lab are a selection of transducers. • For each one identify • All the energy transfers (every stage) • Underline useful transfers • Bracket wasted transfers • Write the name and transfers into your books • Example (try in your books in pencil) • Catapult Girl Chemical kinetic elastic kinetic Elastic (sound) gravitational (heat) (heat)

  13. Identifying energy transfers

  14. Energy Transfersrecap Aim: • To define a energy • To explain the purpose of a transducer and their role in the conservation of energy • To identify energy transfers Plenary: on whiteboards • Write down the two most important things you have learnt this lesson.

  15. Efficiency27/11/2014 Aim: • To create sankey diagrams • To calculate efficiency Starter: • Watch the Movie (Roller Coaster) • Identify the energy transfers • How is energy wasted?

  16. Wasted sound energy If you can hear a device that is not designed to make noise then energy is wasted as sound. Examples of devices that waste energy as sound include:

  17. Wasted Heat Energy If a device gets warm and it is not designed to get warm then energy is wasted as heat. Examples of devices that waste energy as heat include:

  18. Which Type of Energy is Wasted?

  19. Wasted Energy • Energy is normally wasted as heat and sound • Wasted energy dissipates (spreads out) into the surroundings. • This dissipated energy is too spread out to do useful work and so cannot be re-used.

  20. Sankey Diagram – A Candle

  21. Sankey Diagram – A Candle Energy in: Every second the candle transfers 100 joules of chemical energy Energy out: 20 joules into light energy and 80 joules into heat energy “Input” energy “Output” energy 20 J light energy 100 J electrical energy 80 J heat energy So each block represents 10J Only the width matters not the length

  22. Sankey Diagram – Running Man

  23. Sankey Diagram - Running Man • Energy in: Every second the man transfers 2000 J of chemical energy • Energy out: ? of useful kinetic, ? of useful sound, ? of wasted heat sound energy 2000 J electrical energy kinetic energy heat energy So each block represents 200 J

  24. Questions • Draw Sankey diagrams for the following on graph paper. • Highlight the useful energy. • Leave the right hand side of the graph paper empty. • Light Bulb input: Electrical 200J output: Light 30J, Heat ?J • Fire input: Chemical 200J output: Heat 150J, Light ?J and Sound 20J • Drill input: Electrical 1000J output: Kinetic 300J, Sound 200J, Heat ?J • Computer input: Electrical ?J output: Sound 50J, Light 100J, Heat 80J and Kinetic 20J

  25. Questions • Make Sankey diagrams for the following on graph paper. • Highlight the useful energy. • Leave the right hand side of the graph paper empty. • Light Bulb input: Electrical 200J output: Light 30J, Heat 170J • Fire input: Chemical 200J output: Heat 150J, Light 30Jand Sound 20J • Drill input: Electrical 1000J output: Kinetic 300J, Sound 200J, Heat 500J • Computer input: Electrical 250J output: Sound 50J, Light 100J, Heat 80J and Kinetic 20J

  26. Energy Efficiency • Definition: • The amount of energy transferred usefully. • Can never exceed 1 or 100%. • Equation: • Efficiency = useful energy out total energy in • It has no Units • It can be a %

  27. Example • A TV Supplies 50J of heat energy, 50J of sound energy, and 100J of light energy. • What is the useful energy out? • What is the total energy in? • Calculate the efficiency of the TV?

  28. Whiteboard Questions

  29. Questions • What is the useful energy out? • What is the input energy in? • Calculate is the efficiency? • Light Bulb input: Electrical 200J output: Light 30J, Heat 170J • Fire input: Chemical 200J output: Heat 150J, Light 30J and Sound 20J • Drill input: Electrical 1000J output: Kinetic 300J, Sound 200J, Heat 500J • Computer input: Electrical 250J output: Sound 50J, Light 100J, Heat 80J and Kinetic 20J

  30. 1) Light Bulb 200 J 170J Heat (wasted) Electrical (total in) 30J Light (useful) • useful energy out = 30J • total energy in = 200J • Efficiency = useful • total • = 30 • 200 • = 0.15 or 15%

  31. 2) Fire Heat (useful) 150J 200 J Light (useful) 30J Chemical (total in) 20J sound (wasted) • useful energy out = 150 + 30 • = 180 J • total energy in = 200 J • Efficiency = useful • total • = 180 • 200 • = 0.9 or 90%

  32. 3) Drill Kinetic (useful) 300J 1000 J Sound (wasted) 200J Electrical (total in) 500J Heat (wasted) • useful energy out = 300J • total energy in = 1000J • Efficiency = useful • total • = 300 • 1000 • = 0.3 or 30%

  33. 4) Computer Sound (useful) 50J 250 J Light (useful) 100J Electrical (total in) 80J Heat (wasted) • useful energy out = 170J • total energy in = 250J • Efficiency = useful • total • = 170 • 250 • = 0.68 or 68% 20J Kinetic (useful)

  34. Multiple-choice quiz

  35. Anagrams

  36. Efficiencyrecap Aim: • To create sankey diagrams • To calculate efficiency