Kepler's second law
Học thuậtThân thiện
Definition
Noun: A fundamental principle of planetary motion stating that an imaginary line connecting a planet to the Sun sweeps out equal areas in equal intervals of time. This law describes how a planet's orbital speed varies depending on its distance from the Sun.
Usage
This term is used in the context of astronomy and physics to describe the non-uniform orbital velocity of planets. * Kepler's second law explains why planets move faster when they are closer to the Sun. * The concept of Kepler's second law is also applicable to the orbits of other celestial bodies, like comets, around a star.
Examples
- According to Kepler's second law, a planet sweeps out equal areas in equal times.
- The varying speed of Earth in its orbit is a direct consequence of Kepler's second law.
- Astronomers use Kepler's second law to calculate the position of a planet along its elliptical path.
Advanced Usage
- The Law of Equal Areas: This is an alternative name for Kepler's second law, emphasizing its geometric description.
- Conservation of Angular Momentum: In advanced physics, Kepler's second law is understood as a manifestation of this conservation principle for a planet orbiting the Sun.
Variants and Related Words
- Kepler's first law: The law stating that planets move in elliptical orbits with the Sun at one focus.
- Kepler's third law: The law describing the mathematical relationship between a planet's orbital period and its average distance from the Sun.
- Planetary motion: The general movement of planets governed by Kepler's laws and Newtonian gravitation.
Synonyms
- Law of equal areas
Related Phrases
- To sweep out equal areas: The key action described by the law.
- The radius vector sweeps out equal areas as the planet orbits.
Noun
- a law concerning the speed at which planets travel; a line connecting a planet to the sun will sweep out equal areas in equal times
- Kepler's second law means that a planet's orbital speed changes with its distance from the sun