Statics

Goals

1. Describe Statics
   
2. Apply Statics effectively

What

Statics is the study of loads (forces, moments, and applied load) acting on a body that is not accelerating — either at rest or moving with constant velocity.

• Load: an interaction that tends to move a body or keep it from moving.
  • Examples: the upward force from a car jack, the downward force on a bridge support, the torque on a bolt, the force of a finger pressing on a keyboard key, the twisting action used to open a jar.
• Body: the object being analyzed. It may be small, like a bolt, or large, like a bridge. In general terms, a body is anything made of atoms.
  • Examples: bridges, knees, highways, bicycles, keyboards, link in a chain, a plastic part, a tooth.

Why Statics is Worth Learning

Loads can cause objects to fail. Statics equips us to analyze loads so we can design things that are less likely to fail. It is also foundational: success in many engineering courses builds on a strong grasp of statics.

How to Excel in Statics

To excel, learn the fundamentals and apply them to each problem. Here are some of the core fundamentals of Statics.

• Modeling: Simplify reality to make it manageable. For example, a bridge is too complex to analyze directly, so we model it in a way that captures the essentials.

• Particles and Rigid Bodies: Represent objects as either particles (size and shape neglected) or rigid bodies (size and shape included, but deformation neglected).

• Free-Body Diagram: Draw the body separate from its surroundings, showing all loads acting on it.

• Equilibrium Equations: Apply the balance conditions:

  • Force equilibrium → all forces sum to zero.
    
  • Moment equilibrium → all torques (rotations) balance.

• Reflection: After solving, interpret your results. What do they mean? Is the design safe? Could it fail?