Equilibrium in 2D: System Isolation and Free-Body Diagrams

This lecture covers the concept of equilibrium in 2D, where bodies are considered in balance if the applied forces and moments do not cause movement or rotation. It explains system isolation, free-body diagrams, and the modeling of joints and supports. Through examples like loading a ladder and analyzing a system of pulleys, the instructor demonstrates how to apply equilibrium conditions and compute reaction forces. The lecture also discusses idealized contacts in 2D, such as smooth and rough contacts, rollers, and cables. Additionally, it explores alternative free-body diagrams and the calculation of forces and moments in equilibrium systems.