PHYSICS 13 Kepler's Laws of Planetary Motion

Which is the correct definition of Kepler's 1st Law of Planetary Motion?

• Planets orbit stars in elliptical orbits, with the star as one focus of the ellipse.

• Planets orbit stars in circular orbits, with the star at the geometric center of the circle.

• Planets orbit stars in oval orbits, with the star moving in small epicircles near the center of the orbit.

• Planets orbit stars in clothoid-shaped orbits, with the star at the equilibrium position within the clothoid.

Which is the correct definition of Kepler's 2nd Law of Planetary Motion?

• As a planet moves through its orbit, it moves equidistant in equal amounts of time.

• As a planet moves through its orbit, it sweeps equal areas between the star and planet orbit in equal amounts of time.

• As a planet moves through its orbit, it moves faster near perihelion and moves slower near aphelion.

• As a planet moves through its orbit, the planet will move faster as the orbital radius increases and move slower as the orbital radius decreases.

Which is the correct definition of Kepler's 3rd Law of Planetary Motion?

• The planet's orbital radius-cubed is proportional to the planet's maximum orbital speed-cubed.

• The planet's orbital period-squared is proportional to the planet's orbital radius-squared.

• The planet's orbital period-cubed is proportional to the planet's maximum orbital speed-squared.

• The planet's orbital speed-squared is proportional to the planet's orbital radius-cubed.

Why do planets in our solar system keep stable, nearly circular orbits?

• Centripetal force is equal to the gravitational attraction between the Sun and the planet.

• Inertial force of the planet is equal to the centripetal force of the planet.

• The planet's orbital speed must remain constant (never changes) as it moves around the Sun.

• The planet's orbital speed has to speed up and slow down because the larger planets (Jupiter and Saturn) have a strong outward gravity pull force counter to the Sun's gravity pull force.

Tags

NGSS.HS-ESS1-4

NGSS.HS-PS2-4

At which position is the planet's orbital speed the fastest?

• Position #1

• Position #2

• Position #3

• Position #4

At which position is the planet's orbital speed getting faster?

• Position #1

• Position #2

• Position #3

• Position #4

Tags

NGSS.HS-ESS1-4

At which position is the planet's orbital speed getting slower?

• Position #1

• Position #2

• Position #3

• Position #4

Tags

NGSS.HS-ESS1-4

NGSS.HS-PS2-4

At which position is the gravitational attraction between the sun and the planet the weakest?

• Position #1

• Position #2

• Position #3

• Position #4

Tags

NGSS.HS-ESS1-4

NGSS.HS-PS2-4

At which position is the gravitational attraction between the sun and the planet increasing?

• Position #1

• Position #2

• Position #3

• Position #4

At which position is the centripetal force of the planet the weakest?

• Position #1

• Position #2

• Position #3

• Position #4