Final answer:
The Euler-Lagrange equation can be altered to show the transition from a catenary shape to a parabolic shape under heavier loads, demonstrating the use of a modified equation of motion.
The Correct Option is; option D.
Step-by-step explanation:
The correct option to show how the shape of a suspended cable with no load is a catenary shape and transforms to a parabolic shape under a heavier load using the Euler-Lagrange equation is option D.
By altering the Lagrangian for a cable under varying loads in the Euler-Lagrange equation, we can obtain a modified equation of motion. This modified equation demonstrates the transition from a catenary shape to a parabolic shape under heavier loads.
This transformation occurs because the increased load on the cable changes the potential energy function, resulting in a parabolic cable shape instead of a catenary.