Plan
I am planning to test five materials (paper, cling film, cloth, bubble wrap and plastic) and one control, three times and find the average (to ensure accuracy). Whichever material changes the temp of the water the least is the best insulator.
I will wrap them around a 200ml beaker (no lid) and fill it with 200ml of boiling water. Then I’ll take the temp eleven times: once at the beginning, and once every min for a period of ten minutes.
Equipment List
Stop watch – 1
Thermometer – 6
200ml beakers – 6
Kettle – 1
Fair Test
The following will be kept the same throughout the whole experiment:
- Method
- Time given to cool
- Equipment
- Conditions
Also some of the variables will be need to be kept the same throughout the whole experiment:
* this is a variable because it changes the amount of convection that happens.
Method
- Prepare the beakers by insulating them with the five materials (except the control) using elastic bands.
- Put water in the kettle and turn it on.
- When the water is hot, pour 200ml into any 3 of the 6 (doing three at a time, gives you more control over the experiment.
- Place thermometers in the beakers.
- Record the start temp.
- Start the stop watch.
- Record the temp every min for ten min.
- Repeat the process for the remaining three.
Prediction
I think that the best thermal insulator will be the bubble wrap due to the fact that it contains trapped air. Trapped air is a good insulator therefore it takes longer for energy to transfer through gasses because the molecules are further part, a vibrating molecule takes longer to hit into another molecule and make it vibrate. The worst thermal insulator will be something that has compact molecules as it is easy for the vibrations to spread throughout.
Results
I did plan to repeat the experiment three times and find the average. However due to a lack of time this did not happen.
Analysis
All the materials are above the control; this gives me the impression that all the materials do have some resistance to the thermal energy that is transferring through the beaker. The graph has a negative correlation which explains, as time goes on the temperature of the water decrease.
The papers final result is 68 and plastics is 67, however they both have same line of best fit, which implies to me that their results are very similar. This may well me that they are equally good insulators.
My prediction was that the bubble wrap was the best insulator because it contains a lot of trapped air. However after completing the investigation, my prediction proved to be incorrect. The best insulator proved to the paper. My only explanation to this is that when the paper was wrapped round the beaker some air became trapped between the paper and beaker and cause and insulation sufficient enough to keep the temperature of the water higher than the rest.
Evaluation
Although this experiment went well I felt that it could have been improved, for example. Having the same length and width of each material would have the experiment much better in fairness. Also I was not able to repeat the experiment twice more due to lack of time which severely affected the accuracy of the results and investigation. Finally having a thermometer for making sure the room temp stays the same
I think that the method was fine and has no problems of any sort except one: testing the room temp and making sure it stays the same.
Conclusion
To conclude, this experiment was seemingly fair, however there is a margin for improvement.
The paper was the best insulator however I think this was an accident due to the trapped air.
I now know that the closer the molecules in an object the better the object is at conducting energy. Which means any thing with trapped air would be a sufficient insulator. This is why they use double glazed windows as an insulator.