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Biology Heat Loss Practical Write Up

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Biology Coursework Practical – Heat Loss The aim of this practical is to find to what extent does the surface area to volume ratio of an object affect the rate of heat loss from the object Hypothesis: As the ratio of surface area to volume of an object decreases the rate of heat loss from the object will also decrease. Objects with the same surface area to volume ratios loose heat at the same rate so long as there are not other variables involved. Background Knowledge: The surface area to volume ratio of an object is determined by dividing the surface area by the volume and putting it into a ratio of one. e.g. A flask of volume 200cm3 and a surface area of 160cm2 will have a surface area to volume ratio of: 160 ---- : 1…show more content…
One the flasks have been filled they will be heated to get the water to 90oC. Once the flasks are both at 90oC bungs will be placed in the top which have thermometers running through them. Using these thermometers the temperature will be recorded every 30 seconds for 20 minutes. This will then be repeated. The experiment is repeated to improve the accuracy of the data. In order to ensure a fair test the experiment will be started at the same temperature each time and will also be allowed to run for the same length of time. Also the depth of the thermometers in each flask will remain constant for both tests. The volume of water will be as equal as possible in both experiments however due to human inaccuracy it is unlikely that the volumes will be exactly the same. Hopefully any variations between experiments will be so small as to be of no consequence. At the end of the experiment the results will be plotted in a table and the average results will be calculated and plotted on a comparative graph so that it is possible to see any variations between the two sets of data. Results: Minutes Temp 100cm3 - 1 Temp 100cm3 - 2 Temp 500cm3 – 1 Temp 500cm3 - 2 Average – 100cm3 Average – 500cm3 0 90 90 90 90 90 90 1 88 88.5 89.5 88.5 88.25 89 2 86 87 88.5 87.5 86.5 88 3 84.5 85 88 87 84.75 87.5 4 83 84 87 86 83.5 86.5 5 81.5 82 86 85.5 81.75 85.75 6 80 80.5 85.5 84.5 80.25 85 7 78 79 84.5 83.5 78.5 84 8 77 78 84
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