The velocity of an earth satellite or other orbiting body at any given point in its orbit.
Related Terms 
ACCELERATION
The rate of change of velocity, as a function of time. Expressed in m/s2.

HELIOCENTRIC PARALLAX
The difference in the apparent direction or positions of a celestial body outside the solar system, as observed from the earth and sun. Also called STELLAR PARALLAX, ANNUAL PARALLAX

ANEMOMETER
An instrument for measuring the velocity of a fluid.

HORIZON
The great circle of the celestial sphere midway between the zenith and nadir, or a line resembling or approximating such a circle. The line where earth and sky appear to meet, and the projection of this line upon the celestial sphere, is called the visible or apparent horizon. A line resembling the visible horizon but above or below it is called a false horizon. The circle of the celestial sphereformed by the intersection of the celestial sphere and a plane perpendicular to the zenithnadir line is called sensible horizon if the plane is through any point, such as the eye of an observer; geoidal horizon if through any sealevel point; and celestial or rational horizon if through the center of the earth. The geometrical horizon was originally considered identi cal with the celestial horizon, but the expression is now more commonly used to refer to the intersection of the celestial

TERMINAL VELOCITY
The highest sustained air stream velocity existing in the mixed air path at the end of the throw.

PARTICLE EROSION
Occurs when fluidentrained particles moving at high velocity pass through orifices or impinge on metering surfaces or sharp angle turns.

CENTRIFUGAL PUMP
Pump which produces fluid velocity and converts it to pressure head.

PARTICLE IMPINGEMENT EROSION
A particulate wear process where high velocity, fluid entrained particles are directed at target surfaces.

SHEAR STRESS
Frictional force overcome in sliding one layer of fluid along another, as in any fluid flow. The shear stress of a petroleum oil or other Newtonian fluid at a given temperature varies directly with shear rate (velocity). The ratio between shear stress and shear rate is constant; this ratio is termed viscosity of a Newtonian fluid, the greater the shear stress as a function of rate of shear. In a nonNewtonian fluid, such as a grease or a polymercontaining oil (e.g. multigrade oil)  shear stress is not proportional to the rate of shear. A nonNewtonian fluid may be said to have an apparent viscosity, a viscosity that holds only for the shear rate (and temperature) at which the viscosity is determined.

SLIP VELOCITY
The phase velocity difference between two phases.
