During stress-testing of heavy marine equipment, engineers measure the tension-extension profiles of two high-performance synthetic polymer mooring lines: Rope Alpha and Rope Beta.
The results are plotted on the graph below:
Describe and explain the mechanical behaviour of Rope Alpha and Rope Beta. Use data from the graph and detailed quantitative calculations of stiffness (stiffness constant) and stored elastic energy up to their limits of proportionality in your answer.