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4008120-208915Year 1000Year 10Edexcel Science143573544069000iGCSE PhysicsHeat Transfers2019-2020Name:________________Physics Teacher:______________HouseCGTest Score3920490-53213000Specification Checklist4.01use the following units: kilogram (kg), joule (J), metre (m), metre/second (m/s), metre/second2 (m/s2), newton (N), second (s) and watt (W)4.02describe energy transfers involving energy stores:? energy stores: chemical, kinetic, gravitational, elastic, thermal, magnetic,electrostatic, nuclear? energy transfers: mechanically, electrically, by heating, by radiation(light and sound)4.03use the principle of conservation of energy4.06describe how thermal energy transfer may take place by conduction, convection and radiation4.07explain the role of convection in everyday phenomena4.08explain how emission and absorption of radiation are related to surface and temperature4.09practical: investigate thermal energy transfer by conduction, convection and radiation4.10explain ways of reducing unwanted energy transfer, such as insulation5429240576500Key WordsKey WordImageDefinitionConduction INCLUDEPICTURE "" \* MERGEFORMATINET In heat?conduction, energy is transferred from molecule to molecule by direct contactConservation INCLUDEPICTURE "" \* MERGEFORMATINET The total amount of some quantity does not changeConvection INCLUDEPICTURE "" \* MERGEFORMATINET Process by which heat is transferred by movement of a heated fluid such as air or waterDensity INCLUDEPICTURE "" \* MERGEFORMATINET Measure of how much matter an object has in a unit volume (cubic meter or cubic centimeter).Efficiency INCLUDEPICTURE "" \* MERGEFORMATINET The percentage of energy that is used for a useful task and how much is wasted.Gravitational Potential INCLUDEPICTURE "" \* MERGEFORMATINET The energy stored in an object by raising it up. If it fell down to the ground all of this would be converted into kinetic/heat.Insulation INCLUDEPICTURE "" \* MERGEFORMATINET Material or process that prevents the transfer of heat by conduction, convection or radiation.Joule INCLUDEPICTURE "" \* MERGEFORMATINET The unit for energy. [J]Kinetic INCLUDEPICTURE "" \* MERGEFORMATINET MovementRadiation INCLUDEPICTURE "" \* MERGEFORMATINET A form of heat transfer by electromagnetic waves (infrared radiation). These are emitted or absorbed by the surface of objects.Thermal INCLUDEPICTURE "" \* MERGEFORMATINET Heat4548505-144145001: Energy RevisionKnowledge and Understanding QuizUse the knowledge you have gained since Shell to answer the following questions:What is the definition of a Galaxy?………………………………………………………………………………………..(1)What is the definition of a Longitudinal wave?…………………………………………………………………………………………………………………………………………………………………………………… (2)State two forms of Energy Store…………………………………………………………………………………………………………………………………………………………………………………… (2)What is the weight of an object on Earth if it has a mass of 500g? ………………… (3) What is the name of the force that causes moons to orbit planets?………………………………………………………………………………………… (1)What is the orbital speed of a planet which has an orbital radius of 7000km and takes 320 days to orbit a star? ………………… (3) A light wave (v = 3 x 108 m/s) has a wavelength of 3mm. What is its frequency? ………………… (3) Score [ /15]4455160-341630005778523749000Learning Outcomes: Recall the 8 energy stores and the 4 forms of energy transfer State the conservation of energy Confidently calculate the efficiency of a system Energy Summary SheetUse your knowledge from Shell to complete the summary below. Stores and TransfersStoresTransfers1.1.2.2.3.3.4.4.5.State the Conservation of Energy.…………………………………………………..…………………………………………………..…………………………………………………..6.7.8.Equations [Add the units next to the equations in green pen]What is the equation for efficiency?What is the equation for gravitational potential energy?What is the equation for kinetic energy?-6350025400004390845-45720000Worksheet – Shell EnergyWorked Example: What are the energy stores/transfers involved when a book falls off a shelf?QuestionsSituationEnergy Stores/TransfersTurning on a Light SwitchRubbing your hands togetherA car driving up a hillPining an elastic band.Bouncing on a TrampolineRunning a marathon4178300-355492002: ConductionKnowledge and Understanding QuizUse the knowledge you have gained since Shell to answer the following questions:A runner is moving at 6m/s and has a mass of 65kg. What is the kinetic energy of the runner? ……..………….. (3)What is the definition of frequency?…………………………………………………………………………………………………………………………………………………………………………………… (1)A seagull has 2.4kJ of GPE and has a mass of 2kg. How high up is the seagull? ……..………….. (3)In what direction does friction always act?………………………………………………………………………………………… (1)What three parts of the EM spectrum are used for communication?………………………………………………………………………………………… (3)Score [ /11]4455160-341630004286322860000Learning Outcomes: Describe how the process of conduction transfers heat. Explain why conduction can only happen in solidsDescribe an experiment that can determine which materials are good conductors. 362902521590Health and Safety Check!Bunsen burner – keep a safe distance, ensure hairis tied back and gogglesare onMetal equipment will get hot during demonstration- do not touch. 00Health and Safety Check!Bunsen burner – keep a safe distance, ensure hairis tied back and gogglesare onMetal equipment will get hot during demonstration- do not touch. 5506720-5048255410835410210L1.ConductionYour teacher will demonstrate conduction through different types of solid. Use the space below to make notes and sketch explanations of what you see. 541020095250-1016001949450Key IdeasConduction is the transfer of heat energy through a solid. Heat is transferred through the vibration of particles but the substance itself does not move. As particles gain energy they vibrate more causing them to ‘bump’ into neighbouring particles, transferring the energy. Heat energy always travels from hot to cold. Metals are better conductors of heat that non-metals (e.g. wood)4388485-57213500Exam Style Question: ConductionAttempt the questions once independently. Make sure you add corrections in green pen after it has been marked. Explain why saucepans are much more common with plastic handles than metal handles.(3)…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………Explain in terms of particles why the egg cooks on the pan in the image below. INCLUDEPICTURE "" \* MERGEFORMATINET (4)……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………Score:Markers comments:4509135-45212000Worksheet – ConductionWhich of the following is the worst conductor of heat? Circle your answer. air, copper, glass, rubber, steelExplain why ………………………………………………………………………………………………………………………………………………………………………………………………………………Why do birds fluff up their feathers to keep themselves warm?………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………Why are metals better conductors than other solids?………………………………………………………………………………………………………………………………………………………………………………………………………………Explain the following:saucepans for use on a hot plate are made with copper bottoms;………………………………………………………………………………………………………………………………………………………………………………………………these bottoms are made as flat as possible;………………………………………………………………………………………………………………………………………………………………………………………………the handle of the saucepans are made of wood or plastic.………………………………………………………………………………………………………………………………………………………………………………………………Why does double glazing reduce the heat loss from a window?………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………Harder QuestionsDescribe a food preparation activity that involves heat transfer by conduction and explain how the rate of this conduction is controlled by the behaviour of or the decisions made by the cook.……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….Describe how animals lose heat to or gain heat from their environment by conduction and explain how the rate of this heat transfer is controlled through physiological or behavioural adaptations.……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….Describe how a typical house loses heat to or gains heat from the environment by conduction and explain how the rate of this heat transfer is controlled by the way in which the building was constructed. ……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….Which is the better (i.e. faster) conductor of heat, a solid rod of copper or a hollow rod of copper of the same length and diameter? Why?……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….4216400-520700003: Convection Knowledge and Understanding QuizUse the knowledge you have gained so far to answer the following questions:Name a type of material that is a good conductor?………………………………………………………………(1)Name the 4 ways energy can be transferred?………………………………………………………………………………………………………………………………………… (4)State Hooke’s Law.…………………………………………………………………………………………………………………………………………………………………………………… (2)The resistance of which electrical component is effected by the intensity of the light shining on it?………………………………………………………………………………………… (1)What state of matter is required for conduction to occur?………………………………………………………………………………………… (1)What is the relationship linking energy, charge and voltage?(1) Score [ /10]4392295-341630004572022542500Learning Outcomes: Describe how the process of convection transfers heat Compare the processes of convection and conduction3441700538480Health and Safety Check!Potassium Permanganate - make sure teacher is in goggles and be aware that the chemical is an irritantNaked flame (candle) - do not touch directly and be mindful that wax can get hot 00Health and Safety Check!Potassium Permanganate - make sure teacher is in goggles and be aware that the chemical is an irritantNaked flame (candle) - do not touch directly and be mindful that wax can get hot 538543524130Explain why convection cannot happen in solids or a vacuum 52451004699000L2. ConvectionYour teacher is going to demonstrate convection in a liquid and a gas. Use the space below to make notes and sketch explanations of what you see.52444651282700-1143001390650Key IdeasConvection can only happen in fluids (liquids or gases)When particles gain energy they spread apart.This results in regions of warmer, less dense fluid which rise (move upwards)When warm regions begin to cool (away from heat source) they increase in density and sink (move downwards)This causes a circulating current which we call a convection current.2227897-57213500Exam Style Question: ConvectionAttempt the questions once independently. Make sure you add corrections in green pen after it has been marked.Explain in terms of particles how a radiator heats up a room. (5)……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………462661024447500………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………Compare the processes of convection and conduction. (5)………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………Score:Markers comments:4509135-45466000Worksheet – Convection and ConductionIn each example below, the object is heated through both conduction and convection. This should be evident in your answers. 2000250444500Why does the potato cook?……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….174688560896500……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….Why does the potato cook?……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….……………………………………………………………………………………………………….4143375-171450004: RadiationKnowledge and Understanding QuizUse the knowledge you have gained since Shell to answer the following questions:An object accelerated from rest at 8m/s2 for 3.5 seconds. What is the final speed of the object? ……..………….. (3)What is the definition of time period?………………………………………………………………………………………… (1)A current of 8mA flows for 12 seconds. How much charge will have passed in that time? ……..………….. (3)In what direction does weight always act?………………………………………………………………………………………… (1)What are the two different units used for density?………………………………………………………………………………………… (2)Score [ /10]42863228600004455160-34163000Learning Outcomes: Describe what sorts of surfaces make good absorbers/emitted of radiation56575321892300Describe what sorts of surfaces make good reflectors of radiationIdentify the type of heat transfer(s) occurring in different scenarios3713797513715Health and Safety Check!Leslie cube can get hot.Handle with care. 00Health and Safety Check!Leslie cube can get hot.Handle with care. L3. RadiationYour teacher is going to demonstrate radiation using a Leslie Cube. Use the space below to make notes and annotations to explains what you see.55171976350914400331470373380033147011941174508500967422102552003474085930270-1778002400300Key IdeasThermal radiation is the transfer of energy by infrared (IR) waves. Infrared radiation can be reflected, emitted and absorbed. Matte/Black surfaces are good emitters/absorbers of radiation but bad reflectors.Shiny/White surfaces are bad emitters/absorbers of radiation but good reflectors. Radiation can happen in a vacuum as it does not need particles.4051935-45466000Worksheet- Convection, Conduction or Radiation? In each of the following situations, identify the method of heat transfer taking place (conduction, convection, radiation). More than one process may be occurring.Hot coffee is stirred with a spoon; the spoon gets hot due to _______________.A chair is placed several feet from a fire in a fireplace. The fireplace has a glass screen. The side of the chair facing the fireplace gets warm because of_______________.A certain type of decorative lamp contains coloured liquids. These liquids form globs that break off and rise to the top of the liquid. The globs rise due to _______________.Near the ceiling of a room the air is warmer. The warm air rises because of _______________.A college student holds the back of his hand near an iron to see if it is hot. Heat is transferred to his hand by _______________.A heater is placed under one corner of a water bed mattress. Warm water moves throughout the mattress because of _______________.A certain type of stainless steel cookware has a layer of copper applied to the bottom to help it heat evenly. The copper transfers heat to the pan by _______________.In a swimming pool, the water near the surface is slightly warmer. The warm water rises because of _______________.One end of a copper rod is placed in a flame of a Bunsen burner. Small pieces of wax placed along the rod melt at progressively larger distance from the flame. Heat is transferred through the rod by _______________.A house burns down. On the house across the street, all of the vinyl siding is twisted and warped by the heat. The heat was transferred across the street by _______________.Warm air over the beach rises while cooler dense air from the ocean rushes in due to _______________.The metal skewer gets so hot that you drop your marshmallow in the campfire because of _______________.A huge rock at the state park gets so hot during the day that you can’t sit on it from _______________.You lay on that same rock at night so that you can keep warm by _______________.A fireman feels a door and it is hot from the fire on the other side due to _______________.The cause of weather systems on earth is _______________.You are in the top bunk of a bunk bed and you want to turn the air conditioner on while your friend on the bottom bunk is fine is caused by _______________.RadiationConvectionConductionHeat TransferMediumDescription/ DetailsWhat does it transfer?-182880-8938260Heat Transfers Summary TableHeat Transfers Summary Table4178300-355492005: InsulationKnowledge and Understanding QuizWhat are the three methods of heat transfer?……………………………………………………………………………………………………… (3)Which two methods of heat transfer require particles?…………………………………………………………………… (2)What types of surface are good emitters of radiation?………………………………………………………………………………………… (2)What types of surface are good reflectors of radiation?………………………………………………………………………………………… (2)-6286591821000A cube weighting 12N has sides of 0.3m. What pressure would the cube exert of the floor? ……..………….. (3)Score [ /12]139700317500004455160-22987000Learning Outcomes: Give examples of insulating materials. Describe how different forms of insulation prevent the transfer of heat by convection, conduction or radiation. Carry out an investigation to test which insulators are the most effective. Insulation1376680120650019945355334000-1143001739900Key IdeasInsulation is used to reduce heat transfer. Heat can be transferred by conduction, convection or radiation. Some examples of insulation include double glazing, reflective surfaces/blankets and fibreglass loft insulation. 4178300-52070000Worksheet: InsulationFor each form of insulation below identify the form(s) of heat transfers being prevented and explain how this happens.Worked example:InsulationPrevented Heat TransfersExplanation9334517780000Double GlazingNow you have a go! InsulationPrevented Heat TransfersExplanation9334514986000Loft Insultation444524955500Foil Blanket24574522542500Vacuum flask444524066500Lid24511035369500Clothing (trapped air)18224521907500Foil food container0-711669003556000-50800Health and Safety Check!Boiling water can scoldskin. Always handle withcare.Glassware is breakable.Do not attempt to pick upbroken glass00Health and Safety Check!Boiling water can scoldskin. Always handle withcare.Glassware is breakable.Do not attempt to pick upbroken glass5430520-508635L4. Investigating Insulating Materials533463594615In this investigation you are going to be investigating theeffectiveness of different types of insulating material.533527033782000You will compare the results of 3 different materialsand one control beaker (no insulation). List your insulation choices below:399669022479000No insulation MethodSet up 4 beakers (1 without insulation and 3 with different types of insulations)Sketch and label a diagram of your set-up belowMake sure each beaker has a lid and a thermometer.Add 200 ml of water to each beakerMeasure the initial temperature of the water and start your stopwatch. Measure the temperature of the water every minute for 15 minutes. Stir the water in the beaker prior to reading the thermometer. Add your results to the results table on the next page. -1270008636000Diagram of your set up [labelled]Prediction:I think that ___________ will be the best insulator, meaning that the temperature of the water in that beaker will _________________________________________________.ResultsTime [mins]Temperature [oC]No insulation0123456789101112131415Was your prediction correct?……………………………………………………………………………………………………………Why did we use a cup with no insulation?…………………………………………………………………………………………………………………………………………………………………………………………………………………………Why did we stir the water before taking a reading for temperature?……………………………………………………………………………………………………………889502273628200Heat TransfersPast Paper QuestionsQ1. A cooling tower is designed to transfer thermal energy away from a power station.(a)??Thermal energy from the power station warms the air inside the cooling tower.Air enters through holes at the bottom of the cooling tower and leaves through the top.Explain why the air moves as shown by the arrows.(4) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (b)??Hot water from the power station is sprayed into the cooling tower, as shown.As it falls through the air, some of the hot water evaporates.The rest of the water is collected and returned as cold water to the power station.Explain how evaporation cools the water.(3) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ?(Total for question = 7 marks)?Q2. Polar bears have thick fur to keep them warm.(a)??This photograph of a polar bear was taken using visible light.Darker colours in this image indicate lower temperatures.Discuss what information the image gives about the temperatures of the objects shown.(2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (b)??The polar bear's fur includes short hairs and longer hairs.These longer hairs are hollow and contain air.(i)??Explain how its fur reduces the amount of thermal energy lost by the polar bear.(2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (ii)??Underneath its white fur, a polar bear has black skin.Discuss how these colours affect the overall amount of thermal energy lost by the polar bear's body.(3) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (c)??The diagram shows another image of the same scene.The image was made during the day using ultraviolet rays from the Sun. Brighter colours in this image indicate larger amounts of ultraviolet radiation. The grey line is added to show the position of the polar bear.(i)??Compare the absorption and reflection of ultraviolet rays by the objects shown in the image.(2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (ii)??Suggest why the sky appears dark, even though the Sun emits ultraviolet rays.(1) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (iii)??The hollow hairs in polar bear fur are transparent tubes filled with air.It was thought that these hairs could act like optical fibres and guide ultraviolet rays down to the polar bear's skin.It is now known that this idea is incorrect. The ultraviolet rays do not reach the polar bear's skin.The diagram shows an ultraviolet ray entering the air inside a hollow hair.Suggest why this radiation does not pass down to the polar bear's skin.(2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ?(Total for question = 12 marks)?Q3. The diagram shows a metal device for cooking potatoes.Potatoes are pushed onto the metal spikes.The photograph shows two potatoes cooking in an electric oven. The inside of the oven is black. The heating element is at the bottom of the oven.Describe the different ways in which energy is transferred to cook the potatoes.(6) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ?(Total for question = 6 marks)Q4. A student feels cold at night and decides to sleep under a thick woollen blanket.(a) Explain how the woollen blanket helps to keep the student warm.(4)??????.............................................................................................................................................??????.............................................................................................................................................??????.............................................................................................................................................??????.............................................................................................................................................??????.............................................................................................................................................??????.............................................................................................................................................??????.............................................................................................................................................??????.............................................................................................................................................??????.............................................................................................................................................??????.............................................................................................................................................(b) The student saysDo you agree with the student?Explain why.(1)??????.............................................................................................................................................??????.............................................................................................................................................??????.............................................................................................................................................??????.............................................................................................................................................(Total for question = 5 marks)Q5. A student has two computer hard drives.One is black and one is white.The student places the white hard drive on top of the black one as shown in photograph A.The student connects both hard drives to a computer so that they receive the same amount of electrical power. The temperature of the hard drives rises as they work.The student then rearranges the hard drives so that the black one is on top as shown in photograph B.The hard drives are still working, but their temperature is lower than before.Explain why the hard drives work at a lower temperature when the black one is on top.(4)............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................?(Total for question = 4 marks)913130243014500Heat TransfersSpec Point NotesHeat Transfers Specification Notes 4.01use the following units: kilogram (kg), joule (J), metre (m), metre/second (m/s), metre/second2 (m/s2), newton (N), second (s) and watt (W)4.02describe energy transfers involving energy stores:? energy stores: chemical, kinetic, gravitational, elastic, thermal, magnetic,electrostatic, nuclear? energy transfers: mechanically, electrically, by heating, by radiation(light and sound)chemical – stored in fuel and food kinetic – movement energygravitational – gained by objects that are raised upelastic – when an object is stretched or compressed eg springsthermal – from hot objectsmagnetic – objects in magnetic fieldselectrostatic – charged objectsnuclear – stored within a nucleus4.03use the principle of conservation of energyEnergy cannot be created or destroyed. (It is just transferred from one store to another.)4.06describe how thermal energy transfer may take place by conduction, convection and radiationConduction is the transfer of thermal energy through a substance by the vibration of the atoms within the substance. Metals are good conductors because they have free electrons that can move easily through the metal, making the transfer of energy happen faster.Convection occurs in a liquid or gas. These expand when heated because the particles move faster and take up more volume – (the particles remain the same size but become further apart).The hot liquid or gas is less dense, so it rises into colder areas. The denser, colder liquid or gas falls into the warm areas. In this way, convection currents are set up which transfer heat from place to place.Thermal radiation is the transfer of energy by infrared (IR) waves.These are part of the EM Spectrum. They travel at the speed of light in a vacuum, and in straight lines.4.07explain the role of convection in everyday phenomena4.08explain how emission and absorption of radiation are related to surface and temperatureLight, shiny surfaces are good reflectors of IR and so are poor at absorbing it. Dark, matt surfaces are poor reflectors and good at absorbing IR. This means that placed next to a heat source, a dark object would heat up faster than a light one.Dark matt surfaces are also best at emitting IR. This means that a hot object with a light shiny surface will emit less IR than a dark matt object at the same temperature.Hotter objects emit more IR per second. The type of EM wave emitted also changes with temperature – the higher the temperature the higher the frequency of EM wave emitted.4.09practical: investigate thermal energy transfer by conduction, convection and radiationCONDUCTION16446517081500CONVECTION800101-52070000RADIATION627697166052004.10explain ways of reducing unwanted energy transfer, such as insulationA good insulating material is a poor conductor that contains trapped air, eg foam, feathers, glass fibre. Being a poor conductor (non-metal) prevents heat transfer by conduction and the trapped air between prevents convection currents from forming-17716520383500Example:The thermos flask below has different design features to prevent heat loss by convection, conduction and radiation. ................
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