Prediction:
My predictions on the experiment is that the cotton insulator will keep the boiling water warmest the longest period. The reason I think this is because cotton is the thickest material from the other material and has a lot of air particles trapped within the cotton (since air is a good insulator.) This causes less conduction. Although foil radiates the heat, its shiny surface absorbs extra heat from the surroundings (endothermic). However I still believe that cotton would be the best material for this experiment. I think the beaker that will have the lowest temperature will be the one with no insulator because it has no material to trap air and the dull surface, which will radiate most heat into the surroundings (exothermic).
Introduction:
There is 3 ways which heat can be lost. The first method is conduction; this is where heat can be transferred from hotter to cooler regions and without movement from the substances.
An example is the one above where a metal pot is placed onto fire. The particles in the metal pot collide and vibrate constantly passing on kinetic energy; the energy is then diffused through the metal pot slowly.
Convection is another method where heat is carried from a hot to cooler region by movement.
As the liquid or gas gets hotter, the particles move faster and cause it to expand and become less denser region.
Radiation is the last method for heat loss; it is transferred by hest energy waves. Radiation is heat “given out” and “taken in” by objects, depending on the surface.
Dark matt surfaces emit more radiation…
5 minutes 5 minutes
later later
100▫C 28▫C !00▫C 54▫C
…than light shiny surfaces at the same temperature.
Dark matt surfaces are better absorbers (Poorer reflectors)…
5 minutes 5 minutes
later later
28▫C 85▫C 28▫C 51▫C
…or radiation then light shiny surfaces at the same temperatures
The black cup has a dark surface that emits more radiation than a white surface at the same temperature. A dark matt surface is better at absorbing heat but is a poor reflector of radiation than a white surface which is at the same temperature. Hot objects mainly emits INFRA-RED radiation which can pass through a vacuum, it doesn’t need different mediums to transfer its energy.
Fair test:
This experiment will be a fair test because there will be equal amount of water, the same iron beakers, one layer of insulators and the time will be identical to the other beakers.
Conclusion:
My prediction about cotton being the best material, to keep boiling water warm for longest was accurate. The second best material was foil; this could have been because the shiny surface reflecting radiation. At several points the foil and cotton were at the same temperatures, this was during the 1st, 3rd and 4th minutes of the experiment. The temperature for the 1st minute was 86▫C, 3rd minute was 79▫C, and 4th minute was 76▫C. However the temperature for foil starts to drop a few Celsius but cotton remains as 76▫C.
In my experiment the stop clock’s timing sometimes ends up a few seconds before the whole minute is over or sometime ends up over the 1 minute by a few seconds. Therefore the experiment was not completely successful. Although overall the experiment showed me which material was best.
Evaluation:
If I was to do my experiment again, I would make the starting temperature at 100▫C by constructing a bigger beaker so there is larger capacity of boiling water, or the iron beaker could be a different material. The timing would be more accurate than the first test done by using a better stop clock that sounds at every minute. I will figure out the temperature by looking at eye level more cautiously to get an exact reading from the thermometer. The experiment will also be done for a longer period so there is a developed analysis of the Heat Loss experiment.
If I had a longer period to do the test, I would do it several times then comparing the results with one another so the temperatures are accurate as they possibly can get. This will build a further better understanding of the investigation that I have planned to do.