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Heat Loss In Coffee Essay Research Paper

Heat Loss In Coffee Essay, Research Paper


Prediction I predict that the best way to keep coffee warm is to have a


silver insulator because of what we know on radiation and silver being a poor


emitter compared to a plain beaker or a black one. I predicted this because


most saucepans are silver because silver is a poor emitter compared to white


and black and also silver? is shiny


which cuts down heat wasted by radiation.Research? ??After making a cup of coffee it loses heat because of the


following factor:·


Radiation ·


Evaporation ·


Conduction ·


ConvectionRadiation The sun radiates heat through


empty space in the form of tiny waves. If you absorb any of the Sun?s


radiation, it heats you up. This is why it is sometimes called Heat radiation.


Everything gives off some heat radiation. The hotter it is the more it


radiates. A black area absorbs much more radiation than a white surface. Much


of the radiation that hits a white surface reflects away. A silver surface is a


poor absorber and good reflector. An example of radiation is a saucepan. (A


saucepan loses heat with radiation and conduction. Also it loses heat by


convection by air currents rising above the saucepan.)Evaporation Evaporation works in a similar way to conduction. When the


beaker or water is heated the molecules vibrate more at different speeds. Every


so often, one molecule will gain a lot more speed than the others and will


escape. When it finally escapes it all it?s energy with it so less is left


behind. Now that there is less energy they are cooler. Conduction This is the only method of heat transfer that happens in


opaque solids. In the solid the particles are fixed. When heat is added they


start to vibrate one by one banging into their neighbouring particle. This is


how heat energy is passed on from one particle to the next. Good conductors are


metals such as gold, silver and glass. A glass beaker can be safety heated on a


gauze because a gauze conducts heat away from a flame. ConvectionThis method of heat transfer mainly occurs in liquid and


gas. In our experiment the water lost heat by convection because the hot water


at the bottom density decrease so it rose to the top and cooled. The slightly


cooler water descended towards the bottom creating a circulatory motion Variables To make the experiment a fair test the starting temperature


was kept to as near as possible. We did not change the amount of water used so


it would be fair. ?Same Vary Amount of water Insulator Size beaker Safety To make sure that this experiment was safe we were careful


pouring the hot water by holding the measuring cylinder with a cloth. ObservationsIn this experiment we will be taking the temperature every


one minute up to ten minutes. To make this a fair and accurate test we will be


repeating the experiment again. Apparatus ·


3C


beaker size 250ml ·

r />

Thermometer ·


Silver foil ·


Black paper ·


Kettle ·


Sellotape ·


Scissors To Test for Radiation ??????????????????????????????????????????????????????????????????????? Wrap the


beaker in silver foil and black paper and plain and see what is the best


insulator.See what dye


is the best yellow or black Method . Set


up apparatus as shown with a thermometer inside it.. Heat


up the water and pour into the beaker..


Quickly take the temperature every minute up to ten minutes and record in the


results.Results Table for insulators Minutes Black 1 Silver 1 Plain 1 Black 2 Silver 2 Plain 2 Black 3 Silver 3 Plain 3 0 85 86 85 84 83 82 75 78 73 1 73 75 72 72 74 73 70 71 71 2 70 73 69 70 72 71 68 69 68 3 68 71 67 67 70 62 66 67 66 4 65 68 66 65 67 61 65 65 63 5 64 67 63 64 66 60 63 64 61 6 62 66 61 62 64 60 62 63 59 7 61 64 59 61 63 59 60 61 59 8 60 62 58 58 61 57 59 60 58 9 59 61 57 58 60 55 58 59 56 10 58 60 55 57 58 54 57 58 53 Result table for dye Minutes Yellow Dye 1 Black Dye 1 Yellow Dye 2 Black Dye 2 0 82 85 75 74 1 77 74 68 64 2 74 71 67 63 3 71 68 65 61 4 69 66 64 60 5 67 64 62 59 6 66 62 61 57 7 64 60 59 55 8 63 59 57.5 54 9 62 57 56 52 10 60 56 55 52 The starting temperatures are starting at different


temperatures, which make the graph unfair. So I need to work out the


temperature change so I can plot an accurate graph. Minutes Average Black Average Change In Black Average Plain Average Change In Plain Average Silver Average Change In Silver 0 81 0 80 0 82 0 1 72 9 72 9 73 9 2 69 12 70 10 71 11 3 67 14 65 15 69 13 4 65 16 63 17 67 15 5 64 17 61 19 66 16 6 62 19 60 20 64 18 7 61 20 59 21 63 19 8 59 22 58 22 61 21 9 58 23 56 24 60 22 10 57 24 54 26 59 23 Minutes Average Yellow Dye Average Change In Yellow Dye Average Black Dye Average Change In Black Dye 0 79 0 80 0 1 73 6 69 11 2 71 8 67 13 3 68 11 65 15 4 67 12 63 17 5 65 14 62 18 6 64 15 60 20 7 62 17 58 22 8 60 19 57 23 9 59 20 55 25 10 58 21 54 26 Conclusion My prediction was right silver is the best insulator. I know


this because at ten minutes silver has not had such a big temperature change


compared to the others. We know that heat is being lost because of the graph


temperature change is increasing as the time is increasing.EvaluationI think that during this experiment we use our apparatus


accurately by having the same size beaker and measuring cylinder. I think that


our experiment wasn?t extremely accurate because of the cooling down at the


start. This caused different starting temperature but because the table and


graph recorded the change it didn?t affect too much. ??????????? In my graph


it shows that Silver is the best followed by black and plain last. On the other


further experiment it showed that yellow dye was better than black dye. I


thought that my experiment went well but that human error must have been caused


because it was difficult at one time because of measuring and recording all of


them at the same time this showed in my plain line where the circled point


didn?t fit in.

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