Variables
Independent Variable: Load (kg) the masses which I am applying to the elastic band.
Dependent Variable: Extension (m) to the elastic band
I have used the same equipment throughout the experiment (including the same elastic band) to ensure that the experiment is as fair as possible.
Diagram
Method
The apparatus was set up as shown on the previous page. I measured the ‘extension’ of the elastic band when it was not loaded. Then I loaded the elastic band with the masses, increasing in 100g intervals each time. I allowed the elastic band to stretch and stay in position for 60 seconds before taking a reading. To ensure that my measurements were as accurate as possible I used a meter ruler which was clamped onto the retort stand so that the elastic band hung next to it. I could then measure the extension using a set square flat against the end of the ruler to read of the measurements. After I had put on all 12 masses I took them all off one by one measuring the elastic band as I unloaded it.
Results
Analysis
I thought that my graph/results would show a proportional increase between the load of the elastic band and the extension, this is shown to be the case.
(See graph for working)
Modifications
I did not have to make any changes to the original plan as I followed the instructions and everything worked. If I had more time then I would have repeated the experiment, as this would have meant that I would be able to take averages and therefore reduce any anomalies.
Evaluation
My uncertainty is + 0.01m because I was using a meter ruler and therefore this was the smallest measurement on it. I could probably improve this uncertainty by using a more precise instrument for measuring it, (probably a vernier scale.) Finding the averages of my results if I had sone the experimant more than once would have helped to ‘improve’ any anomalous results.
Conclusion
My results have shown that my hypothesis was right. I have been able to work out the amount of energy lost in heat by using the area under the two lines of the graph.
