Applied: Systems of Coplanar Forces (Statics)

A. Rigid Body Definition: A rigid body is a body in which the distance between any two points remains unchanged when it is subjected to external forces of any magnitude. Explanation: This means a rigid body does not deform or change its shape under the action of forces. While real-world objects can deform slightly, in mechanics, we often idealize them as rigid to simplify analysis. This allows us to study their motion and equilibrium without considering internal stresses or material properties. Think of it as: Imagine a perfectly stiff wooden block or a solid metal bar. No matter how hard you push or pull on it, its shape and size do not visibly change. Real-world application: Engineers design structures like bridges, buildings, and machine parts by often modeling them as rigid bodies to calculate forces and moments accurately, ensuring stability and preventing catastrophic failure. B.