couple (redirected from couples up)

couple

In physics, a pair of equal parallel forces that are opposite in direction. Couples produce or prevent the turning of a body. The forces used to turn the steering wheel of a car constitute a couple; each hand exerts a force, parallel but opposite in direction, yet they work together to achieve the same goal. A couple is also used to turn a screwdriver or a doorknob, and the pair of forces acting on the opposite poles of a compass needle as it points somewhere between north and south are a couple.

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couple

1. Chiefly hunting or coursing

a. a pair of collars joined by a leash, used to attach hounds to one another

b. two hounds joined in this way

c. the unit of reckoning for hounds in a pack

2. Mechanics a pair of equal and opposite parallel forces that have a tendency to produce rotation with a torque or turning moment equal to the product of either force and the perpendicular distance between them

3. Physics

a. two dissimilar metals, alloys, or semiconductors in electrical contact, across which a voltage develops

b. two dissimilar metals or alloys in electrical contact that when immersed in an electrolyte act as the electrodes of an electrolytic cell

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Couple

A system of two parallel forces of equal magnitude and opposite sense. Under a couple's action a rigid body tends only to rotate about a line normal to the couple's plane. This tendency reflects the vector properties of a couple.

The total force of a couple is zero. The total moment C of a couple is identical about any point. Accordingly, C is the moment of either force about a point on the other and is perpendicular to the couple's plane. See Resultant of forces, Statics

The moment of a couple about a directed line is the component of its total moment in the line's direction. Couples are equivalent whose total moments are equal.