Equilibrum
Equilibrum
Understanding Equilibrium
- Equilibrium is a state in which forces and moments are balanced and there is no net force or net moment acting on a body. Objects in equilibrium are either in rest or moving at constant velocity.
- Equilibrium is a key concept in the study of mechanics, particularly in statics and dynamics.
Types of Equilibrium
- Static equilibrium refers to a situation where a system is not moving. All the forces acting on the body are balanced.
- Dynamic equilibrium indicates that a system is moving with a constant velocity. The forces are still balanced, but the object remains in motion.
Conditions for Equilibrium
- For a body to be in equilibrium, two conditions must be satisfied.
- First Condition: The vector sum of all forces acting on a body must be zero. This is also called force equilibrium.
- Second Condition: The vector sum of all torques or moments acting on a body about any point must be zero. This is known as moment equilibrium.
Practical Examples of Equilibrium
- A book lying on a table is in static equilibrium as the weight of the book is balanced by the reaction force of the table.
- A car moving at a constant speed on a straight road is in dynamic equilibrium. The net force on the car is zero because the forward force (from the car’s engine) is balanced by the backward force (friction and air resistance).
Equilibrium Equations
- Force equilibrium may often be resolved into two or three equations for equilibrium, typically using Cartesian coordinates, ΣF_x = 0, ΣF_y = 0, and (if needed) ΣF_z = 0.
- The summation of moments, is typically represented by: ΣM = 0.
Significance of Equilibrium
- Understanding equilibrium enables us to analyse various real-world systems, from architectural structures to forces acting on a moving car.
- Equilibrium concepts also allow us to understand whether a system is stable or unstable, especially in engineering and construction.