Kepler's Laws

Front

What is Kepler's First Law of Planetary Motion?

Back

Planets move in elliptical orbits with the Sun at one focus.

Front

What is Kepler's Second Law of Planetary Motion?

Back

A line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time.

Front

What is Kepler's Third Law of Planetary Motion?

Back

The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit.

Front

What is the definition of perihelion?

Back

The point in a planet's orbit where it is closest to the Sun.

Front

What is the definition of aphelion?

Back

The point in a planet's orbit where it is farthest from the Sun.

Front

At which point in an elliptical orbit does a planet travel fastest?

Back

At perihelion, when it is closest to the Sun.

Front

At which point in an elliptical orbit does a planet travel slowest?

Back

At aphelion, when it is farthest from the Sun.

Front

What is an elliptical orbit?

Back

An orbit that is oval-shaped, with two foci, one of which is occupied by the Sun.

Front

What role does gravity play in Kepler's Laws?

Back

Gravity is the force that keeps planets in their orbits around the Sun.

Front

How does the distance from the Sun affect a planet's orbital speed?

Back

The closer a planet is to the Sun, the faster it moves in its orbit.