# orbital velocity

orbital velocity
the minimum velocity at which a body must move to maintain a given orbit. Cf. circular velocity.

* * *

velocity sufficient to cause a natural or artificial satellite to remain in orbit. Inertia of the moving body tends to make it move on in a straight line, while gravitational (gravitation) force tends to pull it down. The orbital path, elliptical or circular, thus represents a balance between gravity and inertia. A cannon fired from a mountaintop will throw a projectile farther if its muzzle velocity is increased. If velocity is made high enough the projectile never falls to the ground. The surface of the Earth may be thought of as curving away from the projectile, or satellite, as fast as the latter falls toward it. The more massive the body at the centre of attraction, the higher is the orbital velocity for a particular altitude or distance. Near the surface of the Earth, if air resistance could be disregarded, orbital velocity would be about eight kilometres (five miles) per second. The farther from the centre of attraction a satellite is, the weaker the gravitational force and the less velocity it needs to remain in orbit. See also escape velocity.

* * *

Universalium. 2010.

### Look at other dictionaries:

• Orbital velocity — can refer to the following: The orbital speed of a body in a gravitational field. The velocity of particles due to wave motion, in particular in wind waves. The equivalent velocity of a bound electron needed to produce its orbital kinetic energy …   Wikipedia

• orbital velocity — the minimum velocity at which a body must move to maintain a given orbit. Cf. circular velocity. * * * orbital velocity, 1. the velocity at which a body, as a satellite, revolves about another body: »Orbital velocity is 18,000 miles per hour… …   Useful english dictionary

• orbital velocity — orbitinis greitis statusas T sritis Standartizacija ir metrologija apibrėžtis Greitis, kuriuo kūnas arba dalelė juda tam tikra orbita. atitikmenys: angl. orbital velocity vok. orbitale Geschwindigkeit, f rus. орбитальная скорость, f pranc.… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

• orbital velocity — orbitinis greitis statusas T sritis fizika atitikmenys: angl. orbital velocity vok. orbitale Geschwindigkeit, f rus. орбитальная скорость, f pranc. vitesse orbitale, f …   Fizikos terminų žodynas

• orbital velocity — /ɔbətl vəˈlɒsəti/ (say awbuhtl vuh losuhtee) noun the velocity required to overcome the earth s gravitational attraction and so maintain a satellite in orbit …

• Orbital inclination change — is an orbital maneuver aimed at changing the inclination of an orbiting body s orbit. This maneuver is also known as an orbital plane change as the plane of the orbit is tipped. This maneuver requires a change in the orbital velocity vector… …   Wikipedia

• Orbital mechanics — A satellite orbiting the earth has a tangential velocity and an inward acceleration. Orbital mechanics or astrodynamics is the application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other… …   Wikipedia

• Orbital state vectors — In astrodynamics or celestial dynamics orbital state vectors (sometimes state vectors) are vectors of position ( ) and velocity ( ) that together with their time (epoch) ( ) uniquely determine the state of an orbiting body. State vectors are… …   Wikipedia

• Orbital perturbation analysis (spacecraft) — Isaac Newton in his Philosophiæ Naturalis Principia Mathematica demonstrated that the gravitational force between two mass points is inversely proportional to the square of the distance between the points and fully solved corresponding two body… …   Wikipedia

• Orbital speed — Not to be confused with Escape Velocity. The orbital speed of a body, generally a planet, a natural satellite, an artificial satellite, or a multiple star, is the speed at which it orbits around the barycenter of a system, usually around a more… …   Wikipedia