Lecture
This lecture covers the resolution of equilibrium for a subsystem subjected to three forces, analyzing the balance of a person holding onto a rope. By obtaining the resultant of two forces, the equilibrium of the system of three forces is determined. The lecture demonstrates how the forces must be equal and opposite for equilibrium, with their lines of action intersecting. It explores the impact of lowering the center of gravity on equilibrium and explains how forces can be freely placed as long as their lines of action pass through the center of gravity. The lecture concludes by examining a similar scenario where a person leans on a column, emphasizing the importance of forces being concurrent for stability.