radius vector

noun

, plural radii vec·to·res [vek-, tawr, -eez, -, tohr, -], radius vectors.

1. Mathematics. the length of the line segment joining a fixed point or origin to a given point.
2. Astronomy.
   1. the straight line joining two bodies in relative orbital motion, as the line from the sun to a planet at any point in its orbit.
   2. the distance between two such bodies at any point in the orbit.

radius vector

noun

1. maths a line joining a point in space to the origin of polar or spherical coordinates
2. astronomy an imaginary line joining a satellite to the planet or star around which it is orbiting

radius vector

1. A line segment that joins the origin and a variable point in a system of polar or spherical coordinates.
2. The imaginary straight line that connects the center of the Sun or another body with the center of a planet, comet, or other body that orbits it.

Word History and Origins

Origin of radius vector¹

First recorded in 1745–55

Example Sentences

In a curve referred to polar co”rdinates, any point for which the radius vector is a maximum or minimum.

From Project Gutenberg

So Kepler formulated his second great law of planetary motion very simply: the radius vector of any planet describes, or sweeps over, equal areas in equal times.

From Project Gutenberg

Hodograph, hod′o-graf, n. a curve the radius vector of which represents in direction and magnitude the velocity of a moving particle—a term suggested by Sir W. R. Hamilton.

From Project Gutenberg

Since this is so, we may define Spring by the following geometric representation in which the angle ZOP, made by the radius vector with the fundamental plane, shows a springlike tendency.

From Project Gutenberg

This force is in a direction perpendicular to the radius vector and to the plane containing it and the element of current.

From Project Gutenberg