In my past knowledge and experience I know that material can be effected by three main causes
-Conduction
In conduction the particles vibrate slowly at first, as they absorb heat energy they vibrate faster. They pass the vibration to the adjoining particle. The energy (heat) is transferring along the metal rod. Conduction can only occur in solids as the particles are too far apart. Conduction is the flow of the heat through matter of places of higher temperature places of lower temperature without movement of the matter as a whole.
Red: Heat
Blue: Cold
This picture indicates the particles in a rod; the red particles show the conduction in process and how the energy (heat) is getting pass to the other end of the rod the colder part of the rod.
-Convection
When the particles are heated they rise. This is because the hotter the particles are less dense. When they reach the top, they start to cool down; their density increases so they fall. Convection is the flow of heat through a fluid from places of higher temperature to places of lower temperature by movement of the fluid itself.
In this picture the arrows show the direction of were the convection is taking place. The arrow
Indicates the energy (heat) rising and then falling. When energy (heat) is at the top of the ceiling it cools down and then drops back down.
-Radiation
This is a pure energy wave e.g. the sun’s heat reaching the earth. There is no need for particles. Radiation is the flow of heat from one place to another by means of electromagnet waves. Dull black surfaces are better absorbers of radiation than white shiny surfaces. Black surfaces can also loose its Energy faster than shiny surfaces.
Method:
In my experiment I will be carry out a test to see if polystyrene is a good insulator. I will be repeating the experiment several times to make sure my results are very accurate. In my test I will be measuring how much hot water I put into the polystyrene cup and then measure the temperature of the hot water in the cup. I will repeat this process and then start to add different materials to the polystyrene cup. I will be adding the exact amount of hot water every time I repeat this process. I will be recording the time every minute and will repeating the process several times to make it very accurate.
Safety
In my test I will make sure that my experiment is safe by making sure that I do use the right equipment. I must also make sure that I don’t burn myself with the hot water and be aware of the people in front of me when am holding the hot water.
Equipment
In my experiment I use the following-
- -1 measuring flask: to measure how much water I pour in my tin can.
- -1 tin can : a metal material can that is easily absorbing heat and loose heat
- -1 thermometer: Measures the temperature within its surroundings
- -1 bubble wrap: is an insulator that has trapped air, is made of polystyrene.
- -1 fur: is an insulator that traps heat in its fur, made from animal skin
- -1 stop watch: to measure the speed of something or time something.
- -3 elastic bands: is stretchy and is easily expandable, helps hold things or objects.
Accuracy test
My results 1
In these results they indicate to me that the polystyrene cup wrapped in bubble wrap is the best insulator of the three. This is because trapped air in the bubble wrap allows very little heat out very slowly or reduces the heat loss in the polystyrene cup. The polystyrene cup by itself is the worst insulator of the three and this because there are no layers of material around the cup to help reduce the heat loss.
My results 2
Still in my results this table has again proven that the polystyrene cup with the bubble wrap is the most reliable insulator of the three and is the best of keeping the energy (heat) inside its container. The polystyrene cup itself is also again the worst insulator and easily looses its heat.
My Results 3
My last result show how stable my experiment was. This proves that my test is very accurate and went very well. The test shows that the polystyrene cup with the bubble wrap is still the best insulator and that there is no doubt that is the best insulator of the three. The polystyrene cup with fur is a good insulator but still allows more heat loss than polystyrene in bubble wrap.
Conclusion
In my experiment I discover that bubble wraps a good insulator and how it is very good at keeping trapped air. I also learnt in my experiment that there are 3 main things that can reduce heat or produce heat; they are radiation, convection and conduction. I also learnt that objects that are black are good at absorbing heat energy but can very easily loose that heat energy very fast. This is why black is used on the back of fridges to get the heat out and keep the fridge cool. I also know that silver and shiny objects are good at reflecting heat energy but losses its heat energy very slow.
In my predication I thought that the polystyrene cup with the fur would be the best insulator because it was thick. I disagree with my prediction because the bubble wrap was a better insulator than the fur. This means that the bubble wrap is better at keeping trapped air than the fur.
Evaluation
In my practical my results were successful because I follow my method in which was a successful experiment but could have been better, because I found it hard getting the temperature of the water equal each time to make it a fair test. I was not sure if the water was hotter than it was meant to be or cooler. My experiment could have been a better experiment if I had more time to make sure if everything was accurate, and take more care with the experiments. In my Experiments the test results look very unstable and inaccurate at first, so I did it three times to make sure that I did not go wrong in my first experiment. When I had first look at my results I thought I had done mistakes in my experiments but all the tests were positive and I did not go wrong, and had found out that the bubble wrap was the best insulator. I think that if I knew the exact temperature of the hot water it would give a more accurate test result and this could give me a more reliable result. In my experiments I still think that I have carry out a successful experiment because the test results are reliable and they all have the same pattern in each test I carry out. I think that my results are reliable because I carry it out three times which should give me very accurate result; I think that I am able to write a good conclusion with my result because I did not have much trouble doing my practical.
