Kepler's Laws of Planetary Motion

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 the semi-major axis in an ellipse?

Back

The longest diameter of an ellipse, which runs from one end to the other through the center.

Front

What does the period of a planet refer to?

Back

The time it takes for a planet to complete one full orbit around the Sun.

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

Front

What shape do planets' orbits take according to Kepler's Laws?

Back

Ellipses.

Front

What is the Heliocentric Model?

Back

A model of the solar system where the Sun is at the center and planets orbit around it.

Front

What is the significance of the focus in an elliptical orbit?

Back

It is one of the two points in the ellipse where the gravitational force is concentrated.

Front

How does the speed of a planet change in its orbit?

Back

A planet moves faster when it is closer to the Sun and slower when it is farther away.

Front

What is the relationship between a planet's distance from the Sun and its orbital period?

Back

The farther a planet is from the Sun, the longer its orbital period.