Couple (redirected from coupling 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

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.