- EQUILIBRIUM:
An equilibrium is a status or condition that stays the same over time. There are two kinds:
- A stable equilibrium is one in which tiny disturbances are corrected and the equilibrium maintained or restored.
EXAMPLE: Tip a four-legged chair just an inch, and it falls back to its stable, equilibrium position.
- An unstable equilibrium is a precarious situation in which the slightest change upsets the equilibrium.
Try balancing an empty four-legged chair on two of its legs. It's hard to do, although possible. The reason that it's
so hard is that
even the slightest movement away from the equilibrium point causes the chair to topple further and further,
upsetting the equilibrium.
- Dynamic equilibrium:
A dynamic equilibrium is a type of stable equilibrium in which there are active forces or processes
that always act on unbalanced conditions to restore the balance. The water level in a lake, for example,
generally stays the same (although there may be temporary exceptions) because runoff from incoming streams
and surrounding land areas replenish the water in the lake and too much water in the lake makes the
stream or river draining the lake flow faster.
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