The next best insulator I think is the best is bubble wrap. I think that bubble wrap is the next best insulator because bubble wrap have bubbles, which is trapped of air. Therefore, conduction or radiation cannot take place. This can not take place because air is trapped into the pockets.
The next insulator I think will be good is plastic foam. This is because plastic foam is made from sponge and it has many pores. Heat is prevented from being lost is that it has little holes which then can trap air. However, little conduction and radiation can still take place. I base my prediction on the following
Scientific Background: All metals are good conductors and most non- metals are good insulators. The best insulators are insulators that trap air if the air can’t move then it can’t move then it can’t transfer the heat energy by convection and a bad conductor. Things like blankets. String vests, loft insulation, polystyrene and foam are all good insulators.
The more surface area there is on the boiling tube the more of the hot water will be in contact with the air and so the quicker it will cool.
Insulation such as cotton wool and bubble wrap traps air that is a bad conductor this means that heat is trapped and the test tube stays hot.
Conduction: Conduction is when energy is passed directly from one item to another. If you stirred a pan of soup on the stove with a metal spoon, the spoon will heat up. The heat is being conducted from the hot area of the soup to the colder area of the spoon.
Metals are excellent conductors of heat energy. Other things like wood or plastics are not good conductors of heat energy. These "bad" conductors are called insulators. That's why a pan is usually made of metal and the handle is made of a strong plastic.
Convection: Convection is the movement of gases or liquids from a cooler spot to a warmer spot. If the soup pan above was made of glass, we could see the movement of convection currents in the pan. The warmer soup moves up from the heated area at the bottom of the pan to the top where it is cooler. The cooler soup then moves to take the warmer soup's place. The movement is in a circular pattern within the pan (see picture above).
Convection currents often cause wind. During the daytime, cool air from over water moves to replace the warm air over land that rises. During the nighttime, the directions changes and the water are warmer and the land is cooler.
Radiation: Radiation is the final form of movement of heat energy. The sun's light and heat cannot reach us by conduction or convention because space is almost completely empty. There is nothing to transfer the energy from the sun to the earth. The sun's rays travel in straight lines called heat rays. When it moves like that, it is called radiation.
When the sunlight hits the earth, its radiation is absorbed or reflected. Darker surfaces absorb more of the radiation and lighter surfaces reflect the radiation. So, if you wear light or white clothes outside during the summer, you would be cooler. The below diagram relates to my prediction because I am not investigating colour or day or night.
I think that cotton wool would be the best insulator because cotton wool has little pockets, which can trap air into the pockets and air, wouldn’t be released because air is a very good insulator.
The next insulator I think is going to be the best is bubble wrap. I think this is going to be the next best because it has little bubbles, which can trap air, so no conduction radiation or convection can take place. So therefore, no air can be released.
The next insulator is plastic foam. I think that this is a good insulator because it has many pores that can trap air. In addition, air is a very good insulator. Therefore, no conduction convection or radiation can take place.
Conduction of heat is the process where vibrating particles pass on their extra vibration energy to neighbouring particles like shown below:
Safety
Safety measures are needed because I am dealing with hot water, which can injure. The following things need to be recognized, in order to keep this experiment safe:
Be careful not to knock over the testube with the hot water in
Be careful not to knock over other people’s testube
Care is needed when pouring hot water
Method: I will be taking the readings of the temperature of water for a total 6 minutes.
I am planning to repeat the experiment twice to get an average results.
I was shown a preliminary experiment by my teacher. This helped me because it helped me understand the coursework more clearly. There was also some research I did for myself it also helped other people.
I will do the following to construct my investigation as the following:
First, collect the equipment
Wrap insulator around the boiling tube
Get hot water into beaker
Measure 20cm3 of water pour water into boiling tube
Wait until it reaches 650c
Measure temperature every minute
Repeat experiment twice
Empty results table:
Table showing results of temperature taken every minute for each insulator
Experiment 1 Table showing results of temperature taken every minute for each insulator
Experiment 2 Table showing results of temperature taken every minute for each insulator
Average results table showing temperature taken every minute
A line graph to show average temperature lost every minute for different insulators
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 plastic foam. Altogether I tested three materials and I have discovered which have the best insulating properties. In order from the best insulator to the worst:
Cotton wool – many air pockets trapped inside with air and air is a good insulator
Bubble wrap – many bubbles trapped inside with air and air is a good insulator
Plastic foam – many pores that can trap air and air is a good insulator
In my prediction I had said the cotton wool would be the best insulator, because it has many air pockets trapped inside it and air is an excellent insulator.
I was correct in my prediction. From these statements I therefore conclude that:
Heat loss is reduced when there is an insulator wrapped around the testube
Small pockets of air make an excellent insulator
I did obtain several anomalous results. These results may have been in error because I may have recorded the time at slightly different times when writing down the temperatures. Another reason for the inaccurate results is that I may have moved the thermometer from the middle of the thermometer higher or lower or a little to the left or right.
Evaluation: My method was not 100% a fair test as you can see from my graph. Some of the reasons why there might be errors are:
The water might not have been measured properly because numbers might have been rubbed off from the measuring cylinder
The timing might have been wrong
The insulation might not have been wrapped properly
The water might have lost heat before starting the experiment
Same testube might have been used for the experiment
The same surface are might not have been covered
The equipment and procedures that could have been used to get accurate results are:
Digital thermometers
Digital clocks
The results were good to support my conclusion. Even though there were some errors. Some of the reasons why there might be errors are:
The water might have lost heat will we were waiting to reach the temperature wanted
The timing might have been wrong
Different surface area might have been covered
If I was to do this experiment again I would:
Make sure the same surface area was covered
The same thickness of each insulator
If I were to do the experiment I would use different factors some of the different factors are:
Material – foil, paper, plain copper
Colours – black, white and other colours.
I got my information from
- CGP physics book
A Bar Graph to show average temperature lost
