The material of the vessel could change the rate of heat loss. If it is made from polystyrene it will not allow much heat to pass through it. If it is made of metal then it will allow more heat to pass through it. Room temperature. If the temperature of the room is near the starting temperature of the water then heat process of heat loss will not be as fast. This is because if there is a bigger difference in temperature then the more heat will try to escape. Starting temperature of the water. If the starting temperature is high then the more heat will try to escape. The question I am investigating is “ which material is the best insulation for the lining of a coat?” In the investigation I am going to use three types of material to test. They are: Wool, cotton and bubble wrapping. Throughout conducting my investigation I will take a number of precautions to ensure my experiments fair.
· The water starts at the same temperature.
This will enable me to assess the cooling rate accurately. · The same amount of water is used.
Different amounts of water will largely affect the cooling rate making the experiment inaccurate. · The same amount of material is used.
Although the materials might be different in thickness etc. it is important that they cover the same area. · I will repeat each experiment 2 times.
This allows me to achieve an accurate and fair result.
Out of the three materials that I chose to investigate I think that cotton wool will be the best at reducing the heat loss. I am saying this because inside cotton wool there are many small pockets of trapped air, and air is a very good insulator in small pockets.
I also am suggesting that the control experiment will be the worst because there is no insulation protecting it.
APPARATUS: test tube rack 8 test tubes material 8 thermometers stop clock kettle Elastic bands
METHOD: I will boil some water from the kettle then pour some water from the kettle into each test tube that has been wrapped in the certain material. A thermometer shall be placed into each test tube and the temperature recorded at the beginning of the experiment. I will record the temperature every 5 minutes over a 30-minute period. To make my results reliable I will use a control and test everything I do twice to get an accurate average result.
SAFETY: Safety precautions are needed because I am dealing with hot water, which can scald. The following things need to be acknowledged to, in order to keep this experiment safe:
Ø Be careful not to knock over the vessel with the hot water in
Ø Be careful not to knock over other peoples vessels
Ø Care is needed when pouring hot water
Ø Do not run with the vessel of hot water
RESULTS:
A= average D= decrease in temperature I will calculate temperature fall by subtracting the temperature at the start from the temperature at the end. I will calculate the average temperature drop by dividing the temperature fall by the number of times recorded.
I will draw line graphs to show the results obtained. Like the one below.
OBTAINING EVIDENCE:
Average temperature fall for:
Control= 46-27
= 19oc
Bubble wrap = 48.5-33
= 15.5oc
Cotton = 45-31
= 14oc
Wool = 45-31
= 14oc
As expected the control lost the most heat then the bubble wrap then cotton then the wool.
Average temperature drop for:
Control = 19 ÷ 6
= 3.17 degrees per 5 minutes
Bubble wrap = 15.5 ÷ 6
= 2.58 degrees per 5 minutes
Cotton = 14 ÷ 6
= 2.33 degrees per 5 minutes
Wool = 14 ÷ 6
= 2.33 degrees per 5 minutes
My investigation shows wool was the best insulator then the cotton then bubble wrapping then the control. The results are as I expected. My graphs are shown on the next five pages.
CONCLUSION: From looking at my graph and results table I conclude that there is a change at the rate at which the heat transfers through the experiment. Altogether I tested three materials and I have discovered which have the best insulating properties. In order from the best insulator to the worst:
In the first graph there is the largest drop as this one is the control experiment showing that no insulation, increases the rate of heat loss. The second graph shows a lesser fall but larger than graphs 3 and 4. This is the bubble wrap showing that it is a good insulator but not the best. Graphs 3 and 4 are very similar apart from a few points that are different. They are equal and the best as they are wool and cotton. They have lost the least amount of heat.
I have now found a suitable material for the lining of a jacket that could be worn to the artic. I have also found out that humans keep a constant body temperature no matter what the environmental conditions. They do this by homeostasis. We need extra insulation from clothes because this keeps body heat from escaping and keeps us warm. By wearing clothes the speed at which the heat is lost is reduced. The experiment I carried out was an example of this. I think the material I have found to be the best insulator is good because it traps small particles of air creating more air pockets which in turn keeps more heat in.
EVALUATION: I feel that the experiment I carried out was not as fair as I would have liked it to be. I could have had the temperatures at the start all-equal; I could have measured my volumes more accurately and used more precise amounts of material on the test tubes to make the test fairer. I also feel that I could have made my readings more accurate and take a larger amount of timings for more results. I feel the experiment would have been improved if I had done all these things very precisely and maybe I would have slightly better results. Even though my experiment was not exactly the best my prediction still matched my results in the end, that the wool was the best then cotton then bubble wrap then the control. I do feel that I can conclusively say that wool would be the best lining for a jacket to keep someone warm in the arctic because it traps pockets of air creating warmth. I did find some strange results in my results. This may be down to the impreciseness of my work. In the cotton experiment the temperatures of my first test and second test were the same. I feel that this was my most precise experiment. I have designed an experiment and carried it out. I have obtained results, plotted them on a graph and explained what I have found. I have finally concluded that I will use wool in the lining of my jacket.
