Astronomy Ch. 3 Practice Test – Flashcards
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Suppose the planet Uranus were much brighter in the sky, so that it was as easily visible to the naked eye as Jupiter or Saturn. Which one of the following statements would most likely be true in that case?
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A week would have eight days instead of seven.
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How does a 12-month lunar calendar differ from our 12-month solar calendar?
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It has about 11 fewer days.
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Which of the following best describes a set of conditions under which archaeoastronomers would conclude that an ancient structure was used for astronomical purposes?
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The structure has holes in the ceiling that allow viewing the passage of constellations that figure prominently in the culture's folklore, and many other structures built by the same culture have ceiling holes placed in the same way.
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How did the Ptolemaic model explain the apparent retrograde motion of the planets?
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The planets moved along small circles that moved on larger circles around the Earth.
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When Copernicus first created his Sun-centered model of the universe, it did not lead to substantially better predictions of planetary positions than the Ptolemaic model. Why not?
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Copernicus used perfect circles for the orbits of the planets.
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Earth is farthest from the Sun in July and closest to the Sun in January. During which Northern Hemisphere season is Earth moving fastest in its orbit?
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Winter
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According to Kepler's third law (p2 = a3), how does a planet's mass affect its orbit around the Sun?
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A planet's mass has no effect on its orbit around the Sun.
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All the following statements are true. Which one follows directly from Kepler's third law (p2 = a3)?
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Venus orbits the Sun at a slower average speed than Mercury.
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Suppose a comet orbits the Sun on a highly eccentric orbit with an average (semimajor axis) distance of 1 AU. How long does it take to complete each orbit, and how do we know?
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1 year, which we know from Kepler's third law.
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Galileo challenged the idea that objects in the heavens were perfect by _________.
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observing sunspots on the Sun and mountains on the Moon
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Galileo observed all of the following. Which observation offered direct proof of a planet orbiting the Sun?
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Phases of Venus
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Which of the following is not consistent with the major hallmarks of science?
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Science consists of proven theories that are understood to be true explanations of reality.
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Which of the following is not part of a good scientific theory?
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A scientific theory cannot be accepted until it has been proven true beyond all doubt.
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Only one of the statements below uses the term theory in its correct, scientific sense. Which one?
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Einstein's theory of relativity has been tested and verified thousands of times.
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The astrology practiced by those who cast predictive horoscopes can be tested by __________
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comparing how often the predictions come true to what would be expected by pure chance.
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Imagine for a moment that despite all the evidence, Earth actually is not rotating and orbiting the Sun. Which of these hypothetical observations (none of them are real) would be inconsistent with our Sun-centered view of the solar system?
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We discover a small planet beyond Saturn that rises in the west and sets in the east each day.
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What practical value did astronomy offer to ancient civilizations?
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It helped them keep track of time and seasons, and it was used by some cultures for navigation.
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Scientific thinking is _________.
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based on everyday ideas of observation and trial-and-error experiments
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The names of the seven days of the week are based on _________.
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the seven naked-eye objects that appear to move among the constellations
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The Metonic cycle is
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used to keep lunar calendars approximately synchronized with solar calendars.
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Ptolemy was important in the history of astronomy because he _________.
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developed a model of the solar system that made sufficiently accurate predictions of planetary positions to remain in use for many centuries
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The ancient Greeks get a lot of attention for their contributions to science because _________.
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they were the first people known to try to explain nature with models based on reason and mathematics, without resort to the supernatural
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What do we mean by a geocentric model of the universe?
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A model designed to explain what we see in the sky while having the Earth located in the center of the universe.
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What was the Ptolemaic model?
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An Earth-centered model of planetary motion published by Ptolemy
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The great contribution of Nicholas Copernicus was to _________.
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create a detailed model of our solar system with the Sun rather than Earth at the center
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The great contribution of Tycho Brahe was to _________.
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observe planetary positions with sufficient accuracy so that Kepler could later use the data to discover the laws of planetary motion
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Which of the following was not observed by Galileo?
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Stellar parallax
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Which of the following statements about an ellipse is not true?
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The focus of an ellipse is always located precisely at the center of the ellipse.
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Which of the following is not one of, nor a direct consequence of, Kepler's Laws?
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The force of attraction between any two objects decreases with the square of the distance between their centers.
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Scientific models are used to _________.
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make specific predictions that can be tested through observations or experiments
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In science, a broad idea that has been repeatedly verified so as to give scientists great confidence that it represents reality is called _________.
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a theory
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Which of the following best describes how modern astronomers view astrology?
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Astrology played an important part in the development of astronomy in ancient times, but it is not a science by modern standards.
