1. The problem statement, all variables and given/known data For my coursework I am to compare how the elastic limit in polyester & cotton varies when the same force is applied to them both. I want to do this because for my coursework I have decided to do why polyester is a good material for football shirts, and why, if it is, better than cotton. So I want to see the elastic limit in them both to compare, but I also want to know if there are any sites that say what materials were used to make football shirts before polyester came about. 2. Relevant equations Not sure, I think it is stress/strain but that may be to work out stiffness. I am so confused. 3. The attempt at a solution I don't get this at all. Someone please help, I can't even find any numbers for it's properties. -- Apologies if this is in wrong forum. If it is please move it, thank you.