This sample paper on Why Is Cotton Wool A Good Insulator offers a framework of relevant facts based on recent research in the field. Read the introductory part, body, and conclusion of the paper below.
Plan: The factor I will be changing is the type of insulator. The factor I will be recording is the temperature of the water in degrees for a total of six minutes. To record the temperature I will use a thermometer. The factors I will keep the same so it is a fair test are:
I have also chosen to do a control experiment without insulation to see if there is a great difference in the heat loss if the container has insulation.
I will then boil some water and when it is boiled I will carefully pour it into a measuring cylinder up the chosen volume (20cmï¿½). I will pour it into the containers and allow it to cool to the chosen starting temperature. Once it reaches the chosen starting temperature then I will start the stop clock and record the temperature at chosen intervals. I will repeat this procedure for the next two containers. I will then repeat the whole experiment one more time to be sure that my results that I will obtain are reliable and reproducible.
Equipment: I will be using the following equipment:
Prediction and hypothesis: Out of the four materials that I have been given to investigate I think that cotton wool will be the best insulator because of 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. This helps prevent convection because air is trapped into the small pockets.
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.