Testing Materials Coursework

For this investigation we are going to use a clamp stand, a hook, a cotton reel, a clamp and weights.  We are going to put the clamp stand on the bench and place the cotton reel, with the sample tied around it, in the clamp.  We will then increase the load on the material until it breaks and finally we will measure the load needed. We will make sure that our work is safe by wearing safety goggles throughout the investigation and keeping the weights away from the bench so that when the sample material snaps the weights won’t fall on the bench, we will also keep well away from the weights so that they won’t fall on our feet. 

Results

The table below shows our results.

I believe that test 3 for the elastic sample is an outlier and should be disregarded.  These results show us that the sample that snapped easiest and therefore had the lowest tensile strength was elastic as it snapped at an average weight of 1.58kg.  The sample with the highest tensile strength was joint between the plastic fishing wire and the string because we didn’t have enough weights to snap them.

Evaluation

Getting the same length of material for every sample, putting all the weights on equally, getting enough material for samples and putting the weights on in the same order were some of the difficulties we had with collecting reliable data for the investigation.  I am quite confident in my conclusions but I believe that they could have been improved.  The investigation could have been improved by, measuring each sample of material previous to the investigation, using weights that were all the same size and shape and having more weights to make sure that all the materials snapped.  If these were all taken into account our results would have been more accurate and it would have been easier to collect reliable data.