|Previous chapters examined forces
that were unbalanced, resulting in acceleration, change in direction or speed.
Equilibrium analyzes forces on objects or systems that are balanced, thus the objects or
systems are at rest or moving at a constant velocity.
For example, all houses, buildings, free-standing structures stay together
and stay standing because a great number of forces were taken into consideration and
balanced correctly by engineers and architects using principles of equilibrium (also known
When analyzing any equilibrium problem, three conditions
must be true:
|1) Fx = 0
3) = 0
|1) all horizontal forces add up to zero
2) all vertical forces add up to zero
3) all twisting, rotating forces add up to zero (called torque, )