Apparatus List:
Method:
Test1: All three experiments must be conducted on heatproof mats; this will catch any spills and stop the test tubes burning the table. I will put seven test tubes close up in a circle, this will simulate the huddle. The glass tubes will represent the penguins bodies the hot water will represent the penguins body heat. I will first secure the test tubes together with two elastic bands one at the top and one at the bottom. These will hold the test tubes in place. Then I will put the test tubes into one beaker this will hold the test tubes up and catch any drips of hot water. Then I will fill each tube with boiling water the test tubes will be filled with 10ml of boiling. I will measure the temperature of the inner test tube and one of the outer tubes every minute this will tell me how much quicker the outer tubes temperature drops than the inner test tube. When all the information is gathered and put into my table, I will then make two graphs one for the inner test tube and one for the outer test tube. This will enable me to compare the two temperatures.
Test2: this test will be set up in much the same way as test one but there will be a third ring of test tubes. These will be filled with cold water simulating the cold penguins entering the huddle. I will take the temperatures of each ring - inner, middle and outer this will show me which ring absorbs the most heat which gives the least heat and how much quicker the temperature drops over all compared to the test1 results. All this information will be put into a graph for comparing the same way as test1 then I will compare the two graphs to see the difference.
Test3: In test three I will have one test simulating a single penguin a temperature will be taken every one minute. When I have this information then I will be able to compare it with test1 and test2 to see the difference the extra rings of penguins make. If the single penguins heat drops quicker than the penguins in test1 then I will know that penguins huddle to keep warm using the radiation and absorption of there own heat. I will not try to control convection as this would make it unfair.
Prediction: I predict that in test1 the inner rings temperature will drop the slowest because it has six other test tubes giving it there heat through radiation. I think the outer ring will not drop as rapidly as most would imagine because all the test tubes in the outer ring are touching three other test tubes. I predict in test two that temperatures of the inner and middle ring will drop quicker than in test1 because of the cold outer ring absorbing more heat than the outer ring in test1. This is because the hot will always transfer its energy to cold through radiation. In test 3 I think the test tube will get cold slower than test 2 but faster than test1 this is because the single test tube has no strong source of heat to absorb and has no really cold place to transfer to.
Fair Test: To make this a fair test I will do the test at the same time of day; this is because the room is warmer in the afternoon because of the position of the sun. I will use the same size test tubes in each test; this is because some test tubes maybe thicker than others and let radiate less heat. Make sure the staring temperatures are all the same.
Obtaining Evidence: I have collected my results in a safe environment. Here are my average results in there simplest form:
All temperatures are in degrees C. This data is not fair data because some of the starting temperatures are different but in a graph this will not matter, this is because a graph will show the drop in temperature clearly. So I have made three graphs: minuets
These three graphs show the drop in temperature.
Analysing and Considering Evidence: My results show that the temperature drops in all three tests but at different speeds. This is because in test 1 the inner ring has an outer ring of hot water and an inner ring of hot water this means there is more heat to start with so it will take longer to go down. In test two the inner test tubes heat goes down the quickest out of the three tests because it has a ring of cold water. The hot water gives its energy to the cold water in order to warm it up, this is done through convection. Because the outer test tube is colder than room temperature the energy transfer is greater than that with the air around making the temperature drop quicker than the test 3. The temperature drop shows
Evaluation: The results show that with an outer ring of heat the inner ring’s temperature drops slower. I have compared my results with other groups results which have been almost Identical to mine bringing to the conclusion that the results were in all rather good. There were no strange results and they were as I had predicted. They showed a clear drop in temperature in all three tests. The test went well, but the starting temperatures of the three tests varied slightly which made it slightly unfair. If I re-did the test I would make sure I did all three tests in the morning this is because the sunlight and room temperature will affect my results. I think I have enough strong evidence to support my conclusion. My results all showed the same temperature drop, so I think that shows my results are reliable enough to support my conclusion. I think doing the tests twice will give stronger evidence if one set are not accepted.
Conclusion: With the data I have found I can answer the question ‘Why do penguins huddle?’ I have found that the temperature drops slower when there is more heat, so if a group of penguins huddle they will stay warm longer than a single penguin. This is because of the radiation of heat between each penguin. The group of penguins stay warmer longer due to radiation between each of the penguins; the more penguins the more radiation and the longer the penguins stay warm.
By Tom Jimpson