Astronomy Ch 2 Test Questions – Flashcards
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According to newtons law of universal gravitation if the moon were three times further from the force by Earth on the moon would
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Decrease by a factor of 9
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Which of the following would cause the force on the moon by the Earth to increase by the largest amount
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Move the moon two times closer to Earth
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How does newtons universal law of gravitation explain keplers laws
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Universal gravitation implies thar the planets further from the sun will move more slowly than the planets closer to the sun (Keplers third law) universal gravitation implies that when a planet is closer to the sun inits orbit, it will move faster than when it is further from the sun (keplers second law)
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Geosynchronous satellites orbit at about four earth radii where the earths gravitational pull us
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1/16 g
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During the 18th and 19th centuries attempts to precisely measure the astronomical unit relied largely on rare
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Transits of the inferior planets across the sun
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Today we rely largely on what technique to precisely measure distances in the solar system
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Radar echo timings
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The force of gravity between two objects
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Increases with the masses of the bodies but decreases with the square of the distances between them
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The law of universal gravitation was developed by
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Newton
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If the distance between two astroids is doubled the gravitational force theyvexert on each other will
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Be 1/4th as great
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How much stronger is the gravitational pull of the sun on earth at 1 au than it is on Saturn at 10 AU
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100x
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Jupiter lies about 5 AU from the sun so at its distance
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The suns gravity is 25 times weaker than its pull on the earth
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The force of gravity varies with the
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Product of two masses Inverse square of the distance separating the two bodies
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Given that the plane and overeating nearby star 51 pegasi is about 20x larger than the earth but 400x more massive on that world you would weigh
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400x more than you do here
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The most famous prehistoric astronomical observatory is
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Stonehedge
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The place in a planets orbit that is closest to the sun is called
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Perihelion
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Keplers first law worked where copernicus' original heliocentric model failed because Kepler described the orbit as
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Elliptical but nit circular
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Which of these was a contribution of newton to astronomy
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The moon pulls as strongly on us as we do on it artificial satellites could be put into orbit about the earth his differential calculus lets us calculate planetary motions more accurately the suns gravity is greatest on a planet at perihelion so the planet must speed up
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Upon which point to Copernicus and Kepler disagree
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The orbits of the planets are ellipses with the one focus at the sun
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Tycho Brahes contribution to keplers laws of planetary motion were
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His detailed and accurate observations of the planes position
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During how many portions of the planets orbit with the planet be speeding up the entire time
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Only during one of the portions
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What does Kepler's third planetary motion
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Planet further from the sun orbit at a slower speed in plans closer to the sun
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What contribution to astronomy was made by Tycho Brahe
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The planets orbit around the sun are ellipses not circles
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Escape velocity is the speed required to
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Overcome the gravitational pull of an object
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If the sun and it's masses were suddenly to disappear Earth would
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Fly off into space
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And accurate sketch of Jupiter's orbit around the sun would show
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A nearly perfect circle
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Kepler second law implies what about planetary motion
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Oh planet moves faster when is closer to the sun
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The orbits of two bodies with equal masses under influence of their mutual gravity
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Are identical ellipses with a common focus
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Combining newtons and Kepler's laws that we can weigh the sun provided we know
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The size of the AU and exact length of the year
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Which of these was not seen telescopically by Galileo
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Stellar parallax
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It took two centuries for the compartment can model to replace the ptolmeic model because
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There was no scientific evidence to support either model until Galileo made his observations
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Which of these observations of Galileo review did put Ptolemys cycles
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The complete cycle of Venus phases
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Which of the following is a contribution to astronomy made by Galileo
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The astronomical telescope can show us for more detail than the eye can The moon has craters mountains valleys and dark flood areas on its surface Venus appears most fully lit when it lies on the far side of the sun Jupiter has four moons orbiting it
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A fatal flaw would Ptolemys modelis it inability to predict the observed phases of
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Mercury and Venus
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Which of the following was not a contribution of Galileo to astronomy
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The changing appearance of Saturns rings corresponds to our seasons
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Which of gallows discoveries provided the greatest evidence that the sun must be at the center of the solar system
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That Venus goes through phases
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Which of these was not a telescopic discovery of Galileo
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The moons of Saturn
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Who is considered the father of experimental science
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Galileo
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Galileo found the rotation. The sun was approximately
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One month
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Stonehedge is believed to be an ancient
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3-D calendar
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Scientist today do not except the Potomaic model because
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The work if Tycho ; Kepler showed the heliocentric model was more accurate
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The principal culture that transferred Greek astronomical knowledge to the Renaissance Europe was
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Islamic
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which of these was not a part of the original Copernican model
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Margaree speeds up at perihelion and slows down aphelion
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Which of Galileo's discoveries provided the greatest evidence of the sun must be at the center of the solar system
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That Venus goes through phases
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Which of the following astronomers first pro pose the heliocentric model of the solar system
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Nicholas Copernicus
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The heliocentric model was actually first proposed by
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Aristarchus
