In radiation every object sends out infrared radiation, which is part of the electromagnet spectrum. Hot objects send out more infrared than cold objects. Infrared radiation is reflected by shiny surfaces absorbed by black and rough surfaces and can pass through transparent materials through a vacuum. In radiation dull black is the best colour because black absorbs infrared rays so they heat up quickly and shiny white is the worst as they reflect infrared rays so they heat up slowly. For reflection radiation shiny white will be the suitable and dull black will not. For absorbing radiation shiny white will be the worst and dull black will be the best.
Plan
For this investigation I will be using a data logger instead of using just a simple thermometer to record the temperature. I will use 5 beakers, all of which with different insulators around it. The insulators will be copper, cotton wool, foam, bubble wrap and silver foil. I will test each beaker one at a time. I will first add 100cm of hot water. Then I will set up the data logger. I will set it up as the diagram shown below. I will make sure it is on. Then I will go to the option, graph. Then I will choose the menu. I will then go into set-up and into the time span. Each experiment will be set into a time span of 5 minutes. I will then press acorn + S to start recording. I will have to wait 5 minutes for it to record the results. Then I will press Acorn + V to see the values. I will take the readings at every 30seconds. I will repeat these steps for the other types of materials. To make the experiment safe I will have to be careful of the hot water in the kettle and to make sure I do not spill it near the data logger.
Diagram
Apparatus
For this experiment the equipment I will be using will be: -
- 5 copper beakers and 5 lids
- Data logger (Pocket book and sensor)
- 4 different materials (foam, bubble wrap, cotton wool and silver foil)
- Kettle (hot water)
Fair test: -
To make this experiment a fair test I will: -
- Put a lid on all of the 5 beakers whilst testing.
- I will add equal amount of water in each beaker.
- I will make sure the starting temperature will be the same.
From this experiment the variables will be the materials I use as an insulator on the beaker.
Conclusions
From this experiment cotton wool and silver foil were the best type of material for an insulator and Copper was the worst. You can see from the graph that the line of best fit is almost straight for the cotton wool, foam, bubble wrap and silver foil. This shows that they are all good insulators. Also you can see that the line of best fit for copper is slanting down which means that the water temperature is decreasing.
From the graph there are two anomalous results (circled on the graph). There are for bubble wrap and the foam. These anomalous results have occurred due to incorrect procedures during the experiment. One of the members of my group must have opened the lid of the beakers which then would of let some air out and in return the temperature must have dropped. Due to this accident this section for the experiment was not a fair test.
Silver foil was one of the best types of insulators because it is a bad emitter of heat radiation but it is a good reflector of heat radiation as it reflects the heat back into the copper beaker. Cotton wool was the best type of insulator as it has lots of layers and is very thick and light as it is filled up wit air. It could also trap the air from escaping from the pieces of threads. Copper was the worst type of insulator because it is only one layer thick and very thin.
This experiment shows that silver foil and cotton wool were the two best types of insulators, and then it was foam, followed by bubble wrap and last was copper.
Evaluation
Overall, the experiment I produced went perfectly well. We perfectly decided who did what job for the practical without any arguments. The procedure I used in obtaining my result was to use a data logger to supply me with the temperatures of the waters. I did one beaker at a time but did not manage to repeat my results.
The accuracy of my work was good enough as our results were perfect. Whilst doing the materials foam and bubble wrap we experienced two queer looking results. There results were called anomalous. They occurred, as the data logger was not working properly or we did not manage to keep the fair test very fair as we probably opened the lid of the beakers by accident, which then let some hot air out.
I think that the investigation did produce good results but they did not properly prove my prediction. I predicted that the material, foam would be the best type of insulator but you can see from the set of results that silver foil and cotton wool were the two best. I made a mistake as I underestimated cotton wool because I thought that it was to light to be a good insulator.
If I had the chance to do the investigation again I would improve it by keeping the lid on, I would repeat the results again and obtain the readings at different intervals.
