equilibrium, state of balance. When a body or a system is in equilibrium, there is no net tendency to change. In mechanics, equilibrium has to do with the forces acting on a body. When no force is acting to make a body move in a line, the body is in translational equilibrium; when no force is acting to make the body turn, the body is in rotational equilibrium. A body in equilibrium at rest is said to be in static equilibrium. However, a state of equilibrium does not mean that no forces act on the body, but only that the forces are balanced. For example, when a lever lever, simple machine consisting of a bar supported at some stationary point along its length and used to overcome resistance at a second point by application of force at a third point. The stationary point of a lever is known as its fulcrum.
..... Click the link for more information. is being used to hold up a raised object, forces are being exerted downward on each end of the lever and upward on its fulcrum, but the upward and downward forces balance to maintain translational equilibrium, and the clockwise and counterclockwise moments of the forces on either end balance to maintain rotational equilibrium. The stability of a body is a measure of its ability to return to a position of equilibrium after being disturbed. It depends on the shape of the body and the location of its center of gravity (see center of mass center of mass, the point at which all the mass of a body may be considered to be concentrated in analyzing its motion. The center of mass of a sphere of uniform density coincides with the center of the sphere.
..... Click the link for more information. ). A body with a large flat base and a low center of gravity will be very stable, returning quickly to its position of equilibrium after being tipped. However, a body with a small base and high center of gravity will tend to topple if tipped and is thus less stable than the first body. A body balanced precariously on a point is in unstable equilibrium. Some bodies, such as a ball or a cone lying on its side, do not return to their original position of equilibrium when pushed, assuming instead a new position of equilibrium; these are said to be in neutral equilibrium. In thermodynamics Carnot cycle after the French physicist Sadi Carnot , who first discussed the implications of such cycles. During the Carnot cycle occurring in the operation of a heat engine, a definite quantity of heat is absorbed from a reservoir at high temperature; part of this heat is
..... Click the link for more information. , two bodies placed in contact with each other are said to be in thermal equilibrium when, after a sufficient length of time, their temperatures are equal. Chemical equilibrium chemical equilibrium, state of balance in which two opposing reversible chemical reactions proceed at constant equal rates with no net change in the system. For example, when hydrogen gas, H₂, and iodine gas, I₂
..... Click the link for more information. refers to reversible chemical reactions in which the reactions involved are occurring in opposite directions at equal rates, so that no net change is observed.

equilibrium

Condition in which the net force acting on a particle is zero. A body in equilibrium experiences no acceleration and, unless disturbed by an outside force, will remain in equilibrium indefinitely. A stable equilibrium is one in which small, externally induced displacements from that state produce forces that tend to oppose the displacement and return the body to equilibrium. An unstable equilibrium is one in which the least departures produce forces tending to increase the displacement. A brick lying on the floor is in stable equilibrium, while a ball bearing balanced on a knife-edge is in unstable equilibrium.

equilibrium

1. any unchanging condition or state of a body, system, etc., resulting from the balance or cancelling out of the influences or processes to which it is subjected

2. Physics a state of rest or uniform motion in which there is no resultant force on a body

3. Chem the condition existing when a chemical reaction and its reverse reaction take place at equal rates

4. Physics the condition of a system that has its total energy distributed among its component parts in the statistically most probable manner

5. Physiol a state of bodily balance, maintained primarily by special receptors in the inner ear

6. the economic condition in which there is neither excess demand nor excess supply in a market

equilibrium (redirected from equilibration)

equilibrium

equilibrium
(redirected from equilibration)