Found 1 items, similar to Virtual moment.
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Definition: Virtual moment
, n. [F. moment, L. momentum, for movimentum
movement, motion, moment, fr. movere to move. See Move
1. A minute portion of time; a point of time; an instant; as,
at that very moment.
In a moment, in the twinkling of an eye. --1 Cor.
2. Impulsive power; force; momentum.
The moments or quantities of motion in bodies.
Touch, with lightest moment of impulse,
His free will. --Milton.
3. Importance, as in influence or effect; consequence; weight
or value; consideration.
Matters of great moment. --Shak.
It is an abstruse speculation, but also of far less
moment and consequence of us than the others.
4. An essential element; a deciding point, fact, or
consideration; an essential or influential circumstance.
5. (Math.) An infinitesimal change in a varying quantity; an
increment or decrement. [Obs.]
6. (Mech.) Tendency, or measure of tendency, to produce
motion, esp. motion about a fixed point or axis.
Moment of a couple
(Mech.), the product of either of its
forces into the perpendicular distance between them.
Moment of a force
(a) With respect to a point, the product of the intensity
of the force into the perpendicular distance from the
point to the line of direction of the force.
(b) With respect to a line, the product of that component
of the force which is perpendicular to the plane
passing through the line and the point of application
of the force, into the shortest distance between the
line and this point.
(c) With respect to a plane that is parallel to the force,
the product of the force into the perpendicular
distance of its point of application from the plane.
Moment of inertia
, of a rotating body, the sum of the mass
of each particle of matter of the body into the square of
its distance from the axis of rotation; -- called also
moment of rotation
and moment of the mass
, the product of a force into its leverage;
the same as moment of a force
with respect to a point,
. See under Virtual
Syn: Instant; twinkling; consequence; weight; force; value;
consideration; signification; avail.
(?; 135), a. [Cf. F. virtuel. See Virtue
1. Having the power of acting or of invisible efficacy
without the agency of the material or sensible part;
Heat and cold have a virtual transition, without
communication of substance. --Bacon.
Every kind that lives,
Fomented by his virtual power, and warmed. --Milton.
2. Being in essence or effect, not in fact; as, the virtual
presence of a man in his agent or substitute.
A thing has a virtual existence when it has all the
conditions necessary to its actual existence.
To mask by slight differences in the manners a
virtual identity in the substance. --De Quincey.
Principle of virtual velocities
(Mech.), the law that when
several forces are in equilibrium, the algebraic sum of
their virtual moments is equal to zero.
(Opt.), the point from which rays, having
been rendered divergent by reflection of refraction,
appear to issue; the point at which converging rays would
meet if not reflected or refracted before they reach it.
. (Optics) See under Image
(of a force) (Mech.), the product of the
intensity of the force multiplied by the virtual velocity
of its point of application; -- sometimes called virtual work
(Mech.), a minute hypothetical
displacement, assumed in analysis to facilitate the
investigation of statical problems. With respect to any
given force of a number of forces holding a material
system in equilibrium, it is the projection, upon the
direction of the force, of a line joining its point of
application with a new position of that point indefinitely
near to the first, to which the point is conceived to have
been moved, without disturbing the equilibrium of the
system, or the connections of its parts with each other.
Strictly speaking, it is not a velocity but a length.
. (Mech.) See Virtual moment