radius vector
Học thuậtThân thiện
Definition
- Noun:
- In mathematics and physics, a radius vector is a straight line drawn from a fixed point (called the origin or center) to a variable point, representing the position of that point. It is a fundamental concept in polar, cylindrical, and spherical coordinate systems.
- In astronomy and orbital mechanics, a radius vector is the line segment connecting the center of a celestial body (like a planet or star) to the center of an object (like a satellite or moon) orbiting around it. It describes the object's position relative to the primary body.
Examples of Usage
- Noun:
- In the polar coordinate system, the position of point P is defined by its radius vector and the angle it makes with the polar axis.
- Kepler's second law states that a planet's radius vector sweeps out equal areas in equal times as it orbits the Sun.
Advanced Usage
- The term is often used to describe time-varying vectors in dynamics. For example, "The satellite's radius vector from Earth changes continuously throughout its elliptical orbit."
- In vector calculus, the radius vector (often denoted as r) is a primary variable for describing fields, such as gravitational or electric fields, which are functions of position.
Variants and Related Words
- Position vector: A closely related synonym, especially in mathematics and physics, emphasizing the vector that specifies the location of a point relative to an origin.
- Radial vector: Another term sometimes used interchangeably, highlighting its direction along a radius.
Synonyms
- Position vector
- Radial vector (in specific contexts)
Notes on Meaning
The meaning of radius vector is highly specialized and consistent across its two primary contexts: 1. Geometric/Mathematical Context: A vector from an origin to a point in a coordinate space. 2. Astronomical/Orbital Context: A vector from the center of a primary mass to the center of an orbiting body. In both cases, it is inherently a vector quantity, possessing both magnitude (length/distance) and direction.
Noun
- a line connecting a point in space to the origin of a polar coordinate system
- a line connecting a satellite to the center of the body around which it is rotating