Bio lab report on insulators

Foam is 5 percent air so the air molecules slow down the heat transfer from the liquid, so it stays warmer longer than cotton insulation. This leads me to predict that foam would be the best insulator, as it would trap the heat more, which will cause deficient heat lost. Identification of Variables There are three variables I will take in consideration whilst carrying out my investigation. The independent variable will be the types of materials used for insulation, which will be cotton, newspaper, aluminum foil, and black insulator.

My control variables would be the temperature of the water, 800 Celsius. The pendent variable in my investigation will be the amount of heat loss. Scientific Theory The different types of energy transfers that will be taking place during this experiment will be conduction, convection, insulation, and radiation. Heat is transferred from one material to another through conduction. That happens when the water comes into contact with the cup itself. Materials that are good at conducting heat absorb the heat of the liquid quickly, and therefore, the liquid cools down.

This happens when the heat energy is transferred from the water to the cup and then from the cup to the material around it. If the material is a good conductor, the heat absorbed would be faster so the heat loss from the water itself would increase as well. Insulation reduces heat loss and the rate of cooling. Absorption of heat is slower in materials that are good insulators so the water inside the cup stays warm for a longer period of time.

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Insulation is the restriction of heat. Insulation is also the material used to cause these restrictions.

Insulation is used in houses to keep the heat inside during the winter and outside during hot times. Insulation is also used in blankets, jackets, and drink bottles. Insulation does not create heat; it prevents heat from flowing. Therefore, if you placed a blanket over something cold, it will be cold underneath the blanket. Materials differ in heat conductivity and so also vary in their insulation capacity. When the water will be heated, it will move upwards as a result of the heat.

Warm air will rise and cool air will fall. So convection would be taking place. Then this thermal energy will transfer to the material around the hot water bottle as thermal energy flows from warmer objects to cooler objects. This will cause the material around the water bottle o either absorb energy or to reflect it. Throughout all of these processes radiation would be taking place as the heat would be transferred as energy by particles which will then depending upon the material will either be absorbed or reflected.

Equipment 1 piece of cotton 1 piece of foam 1 sheet of aluminum foil 1 bubble wrap 4 thermometers 2 stopwatches 4 Cups with lids 1 kettle 10 rubber bands 1 piece of play-do 5 beakers Health and Safety Limitations Throughout the experiment, wear goggles Handle the hot water very cautiously Do not put the cups filled with hot water at the edge of the table. Method Prepare water baths at ICC. Take four cups with lids on each one of them and take one more cup without a lid as this is going to be the control for comparison. Cover one of the cups with one layer of cotton. Fix the fabric on the bottle with the help of rubber bands. Pierce the lid, with a thermometer, and fix it to the cap with “Play-do”. Repeat # 3, 4, and 5 with foam, aluminum foil, and bubble wrap and prepare a “control” without a fabric. Measure 200 ml of water in 5 different beakers and pour them into the cups simultaneously with the help of a funnel. Immediately put the cap back on with the thermometer. (Don’t use the same thermometer for all experiments) All five specimens must be carried out concurrently for it to be a fair experiment. Record the temperature from the thermometer every five minutes till 40 minutes have passed (make sure you use a stopwatch for the time). Record your results in a table and present them on a graph. Results Type of material Temperature (0) O (min) 5 (min) 10 (min) (min) ) (min) K) (min) Minimum foil 74 68 65 62 59 56 54 Cotton 80 72 64 61 58 55 52 Foam Bubble wrap 76 67 63 57 No material 69 60 49 46 Analysis In conclusion, out of the materials, aluminum foil, foam, cotton, and bubble wrap, aluminum foil is the best insulator as it restricts the transfer of heat so it slows it down and it reflects the heat energy.

The statistics above indicate that the best insulator is aluminum foil. By examining the results, I can competently say that the rate of heat loss for aluminum foil was very slow. Consequently, it kept water hot for the longest period of time, as the heat absorption occurring was gradual as well. Aluminum is a metal; metals are good conductors of heat and electricity, which means that hey transfer energy from one particle to another. This is known as the collision theory.

However, because aluminum is a shiny metal, it reflects more heat than it absorbs heat which may have caused the reduction of heat retention. The results also indicate that my prognostication at the start was miscalculated or was effected by some incorrect procedures during the experiment. Compared to the control, aluminum foil sis better insulator, which shows that it would absorb heat slower than a normal cup with water, would do. Bubble wrap is the second best insulator as it contains air pockets, which either raps or slows down the heat energy, as it is radiated from the water into the air molecules.

As the heat energy is slowed down, so is the rate of heat retention because the energy through the particles is moving very slowly. When compared to the control, bubble wrap is a better insulator because of the trapping of heat energy inside the air pockets, so the water stays warmer with the bubble wrap on then no material around the cup at all. The material, foam, which I prophesied, is the third best insulator as it is 95 percent air so air molecules from the liquid slow the heat transfer down, so it mains warmer, longer than cotton insulation.

Since the heat transfer is slowed down by the air molecules, the process of heat absorption is also slowed down so by the time heat energy gets to the foam, it is so slow that very less of it can be absorbed. Foam is a good insulator but when it is compared to the control, it is not as good at insulating as the cup without any material. Furthermore, my results show that the cotton is the worst insulator out of all the materials. This maybe because it cannot cause the restriction of heat. It may, however, be a good conductor as it is absorbing heat very quickly as the articles are transferring heat energy at a very fast rate.

Even though it is the worst insulator out of the materials I used in this experiment, compared to the control, which had no material around it, the temperature loss is very close to each other. The temperature in both the cotton and no material is decreasing by either 3 or 4 degrees. So in reality, cotton may act as an insulator but it will not keep either things or people warm for a very long period of time. Even though, the cup without any material is a better insulator than the cotton-insulated cup. Evaluation hind that during my experiment, some things went wrong which made my results less reliable.

The temperatures recorded for all specimens were too close because they were measured by a thermometer. In future when I repeat this experiment again, would use temperature censors to obtain more reliable and accurate results. Also I would repeat the experiment three more times for it to be a fair test. Then I would take an average of the results. Another factor that might have changed the results slightly was that did not cover the cup completely from top to bottom so some parts of it were still exposed to cold IR of the air conditioning.

Also the cups had some tiny holes which I did not cover with play do until half way between the experiment. So for next time, I will need to cover the whole cup rather than just around the cup. One of the other reasons that also caused problem in the results was that all the cups were made out of cardboard which might have contributed to slowing down the heat loss. Undertaking this for next time, I would carry out my experiment in tin cans as they conduct heat rather than insulating heat so it would not affect my results.