- Type of rubber
- Temperature of the rubber band
- Different weights
- Length of rubber band
- Width of rubber band
- Condition of the rubber band
- Kind of rubber band
Method:
- Set up the apparatus as above
- Assure that the long ruler is exactly straight by lining it up with the setsquare.
- Measure the length of the rubber with no weights attached to see what the length of the rubber band is before it is stretched.
- Add a 100g weights until the rubber band is unable to stretch anymore, measure the extension or the rubber band every time one 100g weight is added by using the setsq uare to get a more accurate reading.
- Repeat the experiment so that I compare the results to get the average.
Preliminary Work:
My preliminary work has helped me to choose what variables I am going to use. Here are my preliminary results that helped me to decide what I am going to use.
Prediction:
I predict that as I increase the amount of weights I add the total extension of rubber band will also increase. Here is a scientific theory that backs up my prediction:
Rubber is made up from very long molecules that are called polymers; these are normally all tangled up. When the weights are added to the rubber band the molecules will untangle. When the molecules are completely untangled then they are very difficult to stretch anymore.
Obtaining Evidence
Safety:
- Stand up- you have always got to remain standing while doing the experiment so if an accident occurs then you can get away quickly
- Make sure that there is nothing in your way to prevent any accidents
- Make sure that the apparatus is not at the edge of the table
- Make sure that all the stools are pushed under the table
Here are the results for both the first and second time I carried out my experiment:
Analysing Evidence and Conclusion
My results show that there are no anomalous results and also proves that my prediction is correct, as I the amount of weights added increases the total extension of the rubber band also increases.
As you can see from my graph there is a pattern as the more weights are added the total extension of the rubber band gets larger, this is shown by the more weights added the steeper the gradient.
Evaluating Evidence
I think that the results that I got were very accurate. My results prove that my prediction that I made is correct, I found that my experiment was quite accurate but I could have made some mistakes when I was taking the readings with the setsquare. From my results I can see that there were no anomalous results. I can tell that my results are very reliable, there is not a lot of difference between the first times I carried out the experiment to the second time. If I were to repeat the experiment I would make the experiment more reliable by using weights that are not as heavy this would make the experiment more accurate.
