Final answer:
To determine the force in member AB of the truss, one must analyze the truss structure using static equilibrium principles and solve the system of equations resulting from free-body diagrams.
Step-by-step explanation:
The question asks us to determine the force in member AB of the truss. Looking at the provided strategies and information, the approach involves static equilibrium and free-body diagrams. Initially, the question seems to pertain to several different scenarios involving physics concepts such as equilibrium of forces, tension in cables, and forces exerted by hin-ges. For a truss member force calculation, one would typically use the method of joints or the method of sections and apply equilibrium equations for both the x and y direction, as well as the moment (torque) equilibrium equation if necessary.
However, the given information is fragmented and seems to address different physics problems (e.g., forces on a door, tension in a cable supporting a weight, force on a crane boom). To conclusively answer the specific question regarding the force in member AB, we'd need the complete context for that truss scenario including the geometry of the truss, loadings, and support conditions. It may involve analyzing the truss via the aforementioned methods and solving the system of equations to find the unknown forces.