Module 6

What is the semimajor axis of Saturn if its orbital period is 29 years?

• 3.4

• 4.4

• 8.4

• 9.4

If the perihelion distance of a planet is 740.5 million km and the aphelion distance is 816.6 million km, what is the semimajor axis of the planet's orbit?

• 678.4

• 778.6

• 549.6

• 231.5

Kepler's first law states that the orbit of the planets are

• ellipses with the Sun at one of the foci

• ellipses with the Sun in the center

• always perfectly circular with the Sun in the center

• ellipses with the Earth at one of the foci

Kepler's third law tells us that

• a planet at a given distance from the Sun would have a different orbital period if its orbit were more eccentric

• there is a correlation between a planet's distance from the Sun and the period of its orbit

• there is a relationship among the distances of the planets from the Sun and the number of moons they have

• there is a possibility that there is a tenth planet that can be discovered by measuring its orbit

Kepler's second law states or implies that while traveling in their orbits, the planets

• sweep equal areas in equal times

• move fastest when they are the closest to the Sun

• move slowest when they are the farthest from the Sun

• all of the above

The sum of the perihelion distance and the aphelion distance of a planet's orbit is the

• semiminor axis

• semimajor axis

• major axis

• minor axis

Suppose a star with a mass of 8.59 times the mass of the Sun had a planet that took 32.11 years to orbit the star. At what distance would this planet orbit the star?

• 22.78

• 20.69

• 30.69

• 43.69

Suppose a planet is discovered around a star like the Sun, with a semimajor axis of 22.67. What is its orbital period?

• 102.87

• 108.21

• 102.43

• 107.94

If the semimajor axis of a comet's orbit is 50 and the semiminor axis is 5.0, what is the eccentricity of the comet's orbit?

• 0.995

• 0.546

• 0.322

• 0.499

What is the orbital period of a planet if its semimajor axis is 5.2?

• 12.9

• 15.9

• 11.9

• 10.9