Download Quiz # 4 - Oglethorpe University

Introduction to Descriptive Astronomy
Summer 2012
Quiz # 4
Name: __________________________
1. The most common elements in the universe are
A) about equal amounts of all elements up to iron but very little of any heavier elements.
B) hydrogen and helium, with small amounts of heavier elements.
C) nitrogen and oxygen, with smaller quantities of hydrogen, helium, and heavier elements.
D) heavy elements, with smaller quantities of hydrogen and helium.
2. The most likely mechanism for the solar system is that the
A) Sun and planets slowly condensed to their present form from a gas and dust cloud.
B) Sun captured the planets as they drifted through space.
C) solar system was once a galaxy from which the Sun and planets are the remnants, after evolution.
D) planets were spun out of the Sun as smaller gas clouds and subsequently condensed.
3. Why did the temperature start to rise at the center of the solar nebula?
A) Supernova explosions were stirring up the material there and causing turbulence.
B) The nebula was contracting, which increased the speed of the atoms moving in it.
C) Fusion reactions were beginning in the core, releasing tremendous amounts of heat.
D) Massive stars nearby were heating the nebula with their ultraviolet radiation.
4. The nebular hypothesis of the formation of the solar system assumes that the material that became the
solar system began as a large spherical cloud of gas and dust, rotating slowly. As the solar system
formed, most of this material was transformed into a compact, flattened disk, rotating more rapidly.
What is the explanation for this change in shape and rate of rotation?
A) conservation of angular momentum
B) influence of nearby stars
C) differentiation of materials easily vaporized and not easily vaporized
D) alignment with the plane of the Milky Way Galaxy
5. What are the three “common” substances that are believed to be important in planet formation?
A) electromagnetic radiation, electrical discharges (e.g., lightning), and water
B) rock, ices, and gas
C) solid, liquid, and gaseous hydrogen
D) hydrogen, helium, and neon gases
6. The most probable time sequence for the formation of the solar system was the following:
A) The Sun contracted first as a gas ball, and the planets and moons formed shortly afterward by
accretion and condensation.
B) The Sun formed first, the planets were spun off from the Sun, and the moons in turn were spun off
from the planets.
C) The planets formed first out of a cold nebula of gas and dust, followed by the Sun, which formed
when the gas had become much hotter.
D) The Sun formed initially, and the planets and major moons were captured much later as they drifted
by the Sun.
7. The region at the farthest limits of the solar system in which a large number of objects composed of rock
and ice circle the Sun in a roughly spherical region is called the
A) outer solar system.
B) asteroid belt.
C) Kuiper belt.
D) Oort comet cloud.
8. The asteroid belt exists between the orbits of which planets?
A) Jupiter and Saturn
B) Venus and Earth
C) Mars and Jupiter
D) Earth and Mars
9. The composition of a typical asteroid is
A) rock and metal.
B) ice with a liquid water core.
C) rock and ice.
D) pure ice, or perhaps ice with dust-sized grains of rock mixed in.
10. At what point in time do we say that the protosun became the Sun?
A) when thermonuclear fusion reactions began at its center
B) when it became hot enough to emit light and heat
C) when the temperature began to rise at its center
D) when planetary formation was complete
11. What are the main characteristics of our solar system?
A) four small planets close to the Sun and four large planets far from the Sun
B) three small planets close to the Sun and five large planets far from the Sun
C) two large planets close to the Sun, three small planets next out, and four large planets farthest from
the Sun
D) three small planets close to the Sun, four large planets far from the Sun, and one small planet
farthest from the Sun
12. The overall shape of the orbits of most of the planets in the solar system is
A) perfectly circular.
B) parabolic.
C) slightly elliptical, but nearly circular.
D) elliptical, very elongated.
13. Most of the planets orbit the Sun on or close to the
A) plane of the Milky Way Galaxy.
B) ecliptic plane.
C) plane containing both north and south celestial poles and the zenith at Greenwich, England.
D) equatorial plane.
14. Suppose that observers using the Hubble Space Telescope detect around several solar-type stars the
presence of planets with the following characteristics: low density, large size, fluid surfaces, rapid
rotation. How would these planets be classified in terms of our solar system?
A) asteroids
B) comet nuclei
C) terrestrial planets
D) Jovian planets
15. Which of the following statements is true?
A) The Earth is the biggest of the planets.
B) Jupiter has the highest average density of the planets.
C) The average mass of terrestrial planets is close to the average mass of the large, outer planets.
D) The Earth is the most massive of the terrestrial planets.
I pledge that I have acted honorably.
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Answer Key
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B
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D