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tornadoes
- In tornado: Wind speeds and air pressures
  …suggest that the maximum possible tangential wind speeds generated by tornadoes are in the range of 125 to 160 metres per second, or 450 to 575 km per hour (about 410 to 525 feet per second, or 280 to 360 miles per hour). Most researchers believe the actual extreme value…
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calculation of

luminosity function
- In Milky Way Galaxy: The stellar luminosity function
  …distribution of proper motions and tangential velocities (the speeds at which stellar objects move at right angles to the line of sight) of stars near the Sun.
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orbits
- In mechanics: Circular orbits
  …velocity of the planet is tangent to the orbit. In the absence of gravity, the planet would obey the law of inertia (Newton’s first law) and fly off in a straight line in the direction of the velocity at constant speed. The force of gravity serves to overcome the inertial…
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stellar motion
- In star: Stellar motions
  74 equals the tangential velocity, V_T, in kilometres per second in the plane of the celestial sphere.
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acceleration

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acceleration

physics

Written and fact-checked by The Editors of Encyclopaedia Britannica

Last Updated: Jun 4, 2025 • Article History

Related Topics:: accelerometer; centripetal acceleration; angular acceleration; instantaneous acceleration; uniform acceleration

On the Web:: Khan Academy - What is acceleration? (article) (June 04, 2025)

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acceleration, rate at which velocity changes with time, in terms of both speed and direction. A point or an object moving in a straight line is accelerated if it speeds up or slows down. Motion on a circle is accelerated even if the speed is constant, because the direction is continually changing. For all other kinds of motion, both effects contribute to the acceleration.

Because acceleration has both a magnitude and a direction, it is a vector quantity. Velocity is also a vector quantity. Acceleration is defined as the change in the velocity vector in a time interval, divided by the time interval. Instantaneous acceleration (at a precise moment and location) is given by the limit of the ratio of the change in velocity during a given time interval to the time interval as the time interval goes to zero (see analysis: Instantaneous rates of change). For example, if velocity is expressed in metres per second, acceleration will be expressed in metres per second per second.

The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Erik Gregersen.

tangential velocity

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calculation of

acceleration