Kepler's Laws of Planetary Motion

Questions and Answers

What does Kepler's 1st Law state?

Planets are attracted to the sun by gravitational force.

Planets travel in circular orbits.

Planets travel at constant speed regardless of their distance from the sun.

Planets travel in elliptical orbits with the sun at one focus. (correct)

What does Kepler's 2nd Law indicate about the motion of planets?

A line drawn from the planet to the Sun sweeps out equal areas in equal amounts of time.

What does Kepler's 3rd Law describe?

The period of a planet's revolution around the Sun is proportional to its distance from the Sun.

What is the term for the point in a planet's orbit that is farthest from the Sun?

aphelion Signup and view all the answers

What is the point in the orbit of a planet where it is closest to the Sun called?

perihelion Signup and view all the answers

Define 'area' in the context of geometry.

The number of square units needed to cover a flat surface. Signup and view all the answers

What are 'foci' in relation to elliptical orbits?

Two points used to measure eccentricity, one of which is always the Sun. Signup and view all the answers

Study Notes

Kepler's Laws of Planetary Motion

Kepler's 1st Law states that planets move in elliptical orbits, with the sun located at one of the foci of the ellipse.
This elliptical shape means planets do not travel in perfect circles, influencing their speed and distance from the sun.

Kepler's 2nd Law

According to Kepler's 2nd Law, a line drawn from a planet to the Sun sweeps out equal areas over equal time intervals.
This law indicates variable speeds of planets, where they move faster when closer to the sun and slower when farther away.

Kepler's 3rd Law

Kepler's 3rd Law establishes a relationship between a planet's distance from the sun and its orbital period, suggesting that further planets take longer to complete their orbits.
Specifically, the period of revolution is proportional to the distance from the sun; closer planets have shorter orbital periods and travel faster.

Orbital Points

Aphelion refers to the point in a planet's orbit that is farthest from the sun, affecting its speed and gravitational influence.
Perihelion is the location in a planet's orbit where it is closest to the sun, resulting in increased gravitational pull and orbital speed.

Mathematical Concepts

The term area in the context of these laws refers to the measurement of flat surfaces, important for understanding the distance covered in orbital paths.
Foci are the two fixed points used to define eccentricity in orbit shapes; one of these points is always occupied by the sun, indicating the degree of orbit circularity.

Description

Dive into the fascinating world of astronomy with flashcards that focus on Kepler's Laws of Planetary Motion. Learn about the elliptical orbits of planets and how their velocity changes in relation to the Sun. Perfect for students and enthusiasts alike!