SWK122 Theme 2.5 - Equilibrium in 2D (216 - 239)

What 2 conditions need to be meet to satisfy that an object is in equilibrium

Fr = 0

Mr = 0

This means both the resultant force and resultant moment must be 0

What is a support reaction

A support reaction is a mechanism that is used to prevent the translation of a body by exerting a force on it and prevent the rotation of the body by producing a moment

How is the weight of an object taken into consideration

At this point since most bodys will be homogenous it is a single force acting downloads at the centre of the object

What is the most basic Equilibrium equation. And what are its conditions?

∑Fx = 0

∑Fy = 0

∑Mo = 0

This set of equations has no conditions

What is the 2nd set of equilibrium equations and what are their conditions

∑Fx = 0

∑Ma = 0

∑Mb = 0

The condition for this set of equations is that the line passing through A and B cannot be parallel to the Y axis

What is the 3rd set of equations for equilibrium and what are their conditions

∑Ma = 0

∑Mb = 0

∑Mc = 0

Its condition is that A, B and C may not be on the same line