Chapter 8 Test

Which of the following orbits has the greatest eccentricity?

• 1
• 2
• 3
• 4

What is the orbital period for a planet whose orbit has a semimajor axis of 4 AU?

• 2 years
• 4 years
• 8 years
• 16 years

Which of the following is NOT one of Kepler’s Laws of Motion for orbiting bodies?

• An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force
• A planet orbits the Sun in an ellipse, with the Sun at one focus of the ellipse
• A line connecting a planet to the Sun sweeps out equal areas in equal time intervals
• P2= a3, where P is the orbital period of the planet in years and a is the average distance of the planet from the central star in astronomical units (AU).

Which is the most important factor in determining how long a star will live?

• color
• temperature
• composition
• mass

Elements heavier than iron

• were created during the Big Bang
• are created in the supernova explosions of high-mass stars
• are created by nuclear reactions in stars
• can only be created in a lab

Planets are believed to form

• at the same time as the stars they orbit
• millions of years after the stars they orbit
• only around stars just like the Sun
• around every star in the universe

Where did the heavy elements that make up the bulk of Earth originate?

• supernova
• meteorites
• Big Bang
• the Sun

What is thought to be the age of the eight planets in our solar system relative to each other?

• The inner planets formed together first and the outer planets formed together later
• The outer planets formed together first and the inner planets formed together later
• They all formed at approximately the same time
• They formed sequentially from Neptune inward to Mercury

Kepler’s Third Law of planetary motion describes a relationship between the

• shape of the planet’s orbit and the location of the Sun
• planet’s orbital velocity and its position in its orbit
• distance from the Sun and the time it takes to complete one orbit
• planet’s size and orbital velocity

Which of these statements about Kepler’s Laws is true?

• A planet moves most rapidly when its orbit takes it closest to the Sun
• The time that is required for a planet to complete an orbit is proportional to the square of its radius
• Planets orbit clockwise around the Sun
• Planets travel in circular orbits