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I will make sure each test tube is the same distance from each other, I will do this by making each set touch each other in a circular shape like this: Centre ones measured.
- Same temperature to start with, measuring 65 degrees C each time.
- Left for the same amount of time, 5 minutes each.
Prediction
I predict that the bundle of 25 test tubes will turn out to be the warmest after being left for 5 minutes. I think it will be followed by the 17 bundle, then the 9, then the 5 and finally the one on it’s own will be the coolest. I believe this because:
- Cold air cannot cool them down on both sides as other penguins (or test tubes) are here and so they stay at the same as the thing next to them.
- The penguins do not lose heat from conduction and convection as much because instead of warmth transferring straight from the penguin to the air, the warmth is passed on to penguins that are next to them, this happens in a chain reaction until warmth reaches the end of the bundle. This is why the larger the group, the warmer, I believe, the penguins will be.
Equipment list
- 25 test tubes
- A thermometer
- A stopwatch
- A kettle
- An elastic band to hold the bundles together
- Safety glasses
Preliminary tests
Before I started the experiment I had to test a few things to ensure safety and accuracy:
I tested to see how hot the water was after being boiled in the kettle, tested to see if this was safe and used that temperature to ensure all test tubes were of the same temperature.
I also tested to see if five minutes was long enough to see if any changes had occurred, I realised it was long enough.
Background Information
The three main ways in which things lose heat is conduction, convection and radiation. Conduction is where heat passes through an object; this helps the penguins as heat conducts from penguin to penguin until the end of the bunch. Convection is the process in which hot, less dense air rises. Penguins huddle up to trap hot air and stop it rising into the air above. Radiation is the heat given from the sun, the large surface area of the large groups of penguins ensures that the penguins get maximum heat from the sun, as opposed to one penguin that hardly gets any sunlight and warmth.
Diagram
Conclusion
My prediction was correct in saying that the more test tubes that are huddled up the higher the temperature would be after five minutes. Apart from one anomalous result my prediction was perfect.
I think my anomalous result could have been from a number of things:
- The test tube may have been cracked etc.
- The temperature of the place carried out may have been lower at the time of the anomalous result.
- The kettle may not have boiled up to the normal temperature of 65 Degrees C.
The anomalous result is the only thing to suggest differently to my prediction. I know this was an anomalous result because a) it does not follow the trend and b) After doing it three times both other results were not anomalies.
Evaluation
All in all I think my experiment was a complete success. My prediction matches my results apart from one anomalous result. I think my preliminary tests helped me a lot when it came to the experiment as I felt organised and was assured that nothing in my control could go wrong. Despite this if I were to do the experiment again I would test different variables that could affect Penguin temperature such as their fur. I would also have carried the experiment out with a wider variety of test tubes to confirm what I have found out from this practical. I would have left the test tubes for a longer period of time as penguins huddle up for much longer than I have tested. Finally, I would use the information that I have found out from this experiment and take it one step further by testing my experiment in harsher conditions, as penguins have to face.
