I think it's the one

I think I am going to do the experiment on the strength of different metal wires and I've got the okay. Roughly, what I've decided to do is get 50cm lengths of different wires, e.g. copper, steel, aluminium and zinc and I will hang them all up at the same place. I will then add weights to each of the wires and measure the expansion for each to determine which metal has the least expansion and is the strongest. I will repeat the experiment 3 times and show expansion as a function of weight (line graph). I think that this is very useful information as wires are used a lot to bear mechanical loads. The independent variable in this experiment is weight and the dependent variable is expansion. All the materials that I need are easy to get and I think it should be a reliable experiment.