The Collaborative International Dictionary
Velocity \Ve*loc"i*ty\, n.; pl. Velocities. [L. velocitas, from velox, -ocis, swift, quick; perhaps akin to v?lare to fly (see Volatile): cf. F. v['e]locit['e].]
Quickness of motion; swiftness; speed; celerity; rapidity; as, the velocity of wind; the velocity of a planet or comet in its orbit or course; the velocity of a cannon ball; the velocity of light.
Note: In such phrases, velocity is more generally used than celerity. We apply celerity to animals; as, a horse or an ostrich runs with celerity; but bodies moving in the air or in ethereal space move with greater or less velocity, not celerity. This usage is arbitrary, and perhaps not universal.
(Mech.) Rate of motion; the relation of motion to time, measured by the number of units of space passed over by a moving body or point in a unit of time, usually the number of feet passed over in a second. See the Note under Speed.
Angular velocity. See under Angular.
Initial velocity, the velocity of a moving body at starting; especially, the velocity of a projectile as it leaves the mouth of a firearm from which it is discharged.
Relative velocity, the velocity with which a body approaches or recedes from another body, whether both are moving or only one.
Uniform velocity, velocity in which the same number of units of space are described in each successive unit of time.
Variable velocity, velocity in which the space described varies from instant, either increasing or decreasing; -- in the former case called accelerated velocity, in the latter, retarded velocity; the acceleration or retardation itself being also either uniform or variable.
Virtual velocity. See under Virtual.
Note: In variable velocity, the velocity, strictly, at any given instant, is the rate of motion at that instant, and is expressed by the units of space, which, if the velocity at that instant were continued uniform during a unit of time, would be described in the unit of time; thus, the velocity of a falling body at a given instant is the number of feet which, if the motion which the body has at that instant were continued uniformly for one second, it would pass through in the second. The scientific sense of velocity differs from the popular sense in being applied to all rates of motion, however slow, while the latter implies more or less rapidity or quickness of motion.
Syn: Swiftness; celerity; rapidity; fleetness; speed.
Angular \An"gu*lar\, a. [L. angularis, fr. angulus angle, corner. See Angle.]
Relating to an angle or to angles; having an angle or angles; forming an angle or corner; sharp-cornered; pointed; as, an angular figure.
Measured by an angle; as, angular distance.
Fig.: Lean; lank; raw-boned; ungraceful; sharp and stiff in character; as, remarkably angular in his habits and appearance; an angular female.
Angular aperture, Angular distance. See Aperture, Distance.
Angular motion, the motion of a body about a fixed point or fixed axis, as of a planet or pendulum. It is equal to the angle passed over at the point or axis by a line drawn to the body.
Angular point, the point at which the sides of the angle meet; the vertex.
Angular velocity, the ratio of anuglar motion to the time employed in describing.
n. (context mathematics physics English) The angle turned, in a given time, by a body rotating about an axis; the rate of rotation through an angle.
In physics, the angular velocity is defined as the rate of change of angular displacement and is a vector quantity (more precisely, a pseudovector) which specifies the angular speed ( rotational speed) of an object and the axis about which the object is rotating. This speed can be measured in the SI unit of angular velocity, radians per second, or in terms of degrees per second, degrees per hour, etc. Angular velocity is usually represented by the symbol omega (ω, rarely Ω).
The direction of the angular velocity vector is perpendicular to the plane of rotation, in a direction which is usually specified by the right-hand rule.
Usage examples of "angular velocity".
Within a wide range of speeds, that angular velocity will make a ship take up an orbit at a distance appropriate to its speed.
There was the problem there of the two hour rotation period, which meant the stars whipped across the sky at an angular velocity twelve times that in Earths sky.
There was the problem there of the two hour rotation period, which meant the stars whipped across the sky at an angular velocity twelve times that in Earth’.
Rebka picked one at random and used his suit thrustor to match angular velocity with it.
As soon as the ship entered the first gate like some clumsy croquet ball passing through the first of several thousand wickets, the blade of the accelerator-scissors began snapping open with a differential angular velocity nearing—.
Further south, although the angular velocity is identical, the speed increases.
There was the problem there of the two-hour rotation period, which meant the stars whipped across the sky at an angular velocity twelve times that in Earth's sky.
As the elevator climbed, its angular velocity declined, weakening the centrifugal force of the Stone’.
As the elevator climbed, its angular velocity declined, weakening the centrifugal force of the Stone's rotation.
This is why we concluded the difficulty was in our system, since no sky source moves with such angular velocity.
How, then, assuming equality of angular velocity, could equilibrium be preserved for both?
Unfortunately, since the disk turns at a constant angular velocity, when the needle is in the groove near the outside edge, the speed of the groove past the needle is much higher than the speed near the center of the disk.