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Return to Terminology
V
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- V Rating
- Material to be added.
- Vacuum Stability Test
- Stability Test.
- Valence
- Valence or oxidation state, combining capacity of an Atom
expressed as the number of single bonds the atom can form or the number of electrons an
Element gives up or accepts when reacting to form a compound. The valence of an atom is
determined by the number of electrons in the outermost, or valence, electron shell. An
atom exists in its most stable configuration when its outermost shell is completely
filled; in combining with other atoms, it thus tends to gain or lose valence electrons in
order to attain a stable configuration. The valence of many elements is determined from
their ability to combine with hydrogen or to replace it in compounds.
- Vector
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A quantity having both magnitude
and direction. Many physical quantities are vectors, e.g., force, velocity, and momentum. The simplest representation of a vector is an arrow
connecting two points: [m.ABvector] designates the vector represented by an arrow from
point A to point B, whereas [m.BAvector] designates the vector of equal magnitude from B
to A. In order to compare vectors and to operate on them mathematically, it is necessary
to have some reference system that determines scale and direction, such as Cartesian
Coordinates. A vector is frequently symbolized by its components with respect to the
coordinate axes. Suppose, for example, that the point A has coordinates (2,3) and the
point B has coordinates (5,7). The x-component of [m.ABvector] i.e., its size with respect
to the x-axis, is the difference between the x-coordinates of the points A and B, or 5 - 2
= 3; the y-component is 7 - 3 = 4. Thus [m.ABvector] becomes {3,4}. Knowledge of the
components of a vector enables one to compute its magnitude—in this case, 5, by the
Pythagorean theorem {(32 + 42)1/2 = 5}—and its direction (from Trigonometry). There
are an infinite number of vectors with the components {3,4}, all of which have the same
magnitude and direction; they are considered equal. The concept of a vector can be
extended to three or more dimensions. To add two vectors U and V, one can add their
corresponding components to find the resultant vector R, or one can graph U and V on a set
of coordinate axes and complete the parallelogram formed with U and V as adjacent sides to
obtain R as the diagonal from the common vertex of U and V. The scalar, or dot, product of
two vectors A and B is a nondirectional (scalar) quantity with a magnitude of A·B = |A|
|B| cos ;gu, where ;gu is the angle between A and B. The vector, or cross, product
of A and B is a vector whose magnitude A × B = |A| |B| sin ;gu and whose direction
is perpendicular to both A and B and pointing in the direction in which a right-hand screw
would advance if turned from A to B through the angle ;gu. |
- Vehicle
- In terms of space flight, a structure, machine or device, such
as a rocket, designed to carry a burden through air or space; more restrictively, a rocket
craft.
- Velocity
- 1) Speed.
- 2) A vector quantity equal to speed in a given direction.
- Venturi Tube
- A short tube with varying cross sections and a constricted
throat which controls flow velocity
- Very Pistol
- A firing device for pyrotechnical cartridges.
- Viscosity
- Viscosity, resistance of a fluid to flow. This resistance acts
against the motion of any solid object through the fluid, and also against motion of the
fluid itself past stationary obstacles. Viscosity also acts internally on the fluid
between slower- and faster-moving adjacent layers. All fluids exhibit viscosity to some
degree.
- Viscosity And Consistency
- Related but different rheological (pertaining to flow) terms.
- VOD
- Velocity of detonation, a measure of the rate at which the
detonating wave travels through an explosive charge; the speed of detonation of a
particular explosive. Detonating Velocity.
- Volt
- The unit of voltage or, more technically, of Electric
Potential and Electromotive Force. It is defined as the difference of electric potential
existing across the ends of a conductor having a resistance of 1 OHM when the conductor is
carrying a current of 1 AMPERE.
- Volume Strength
- Same as Cartridge Strength or Bulk
Strength.
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