2) The number one million can be expressed in scientific notation as: (c) a) b) 10 3 c) 10 6 d)

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1 Astronomy Phys 181 Midterm Examination Choose the best answer from the choices provided. 1) What is the range of values that the coordinate Declination can have? (a) a) -90 to +90 degrees b) 0 to 360 degrees c) 0 to 180 degrees d) 0 to 24 hours e) -12 to +12 hours 2) The number one million can be expressed in scientific notation as: (c) a) b) 10 3 c) 10 6 d) e) none of these 3) One minute of right ascension corresponds to how many minutes of arc? (c) a) 1 b) 4 c) 15 d) 60 e) none of these 4) Which of the following stars should be brightest, based on its name? (b) a) Gamma Orion b) Beta Leo Minor c) Delta Leo d) Zeta Ursa Minor 5) Viewed from a position fixed on the celestial sphere, looking downward on the North Pole, the Earth would appear to be rotating: (b) a) Clock-wise b) Counter-clockwise c) Not at all d) Can t say without knowing the precession 6) How long does a complete precession cycle take? (c) a) 4 years b) 6000 years c) 26,000 years d) 60,000years e) one million years 7) The number of stars in a typical galaxy is closest to: (d) a) b) c) d) e)

2 8) The best description of the principle of Bio-convergence might be: (c) a) The reduction of species through natural selection b) Diversification through mutation c) Evolutionary preference for survival traits d) The tendency of one organism to replace another 9) Roughly what fraction of the stars that we see in the sky are binary stars? (a) a) 1/2 b) 1/3 c) 1/4 d) 1/10 e) 1/100 10) Stars with a high mass are not likely to have earth-like planets in orbit around them chiefly because: (c) a) They are too hot b) Their gravitational pull is too strong c) They are too short lived d) They burn too coldly e) They are far too large 11) The fundamental properties of the universe mentioned in lecture are: (b) a) Energy time mass b) Mass time length charge c) Gravity force space time d) Gravitation Electromagnetism Strong Weak e) Energy matter 12) The method used for measuring positions in the sky is called (c) a) The celestial sphere b) A sextant c) Angular measure d) Deferents and epicycles e) estimation 13) One degree is equal to: (e) a) 10 min of arc b) 15 min of arc c) 30 min of arc d) 45 min of arc e) 60 min of arc 14) An object is observed to subtend and angle of 6 when viewed from earth. The same object is then moved to three timed the distance. What angle does it now subtend? (d) a) Impossible to determine without knowing the actual distance b) 12 c) 3 d) 2 e) 1

3 15) 1 Parsec is defined as: (a) a) The distance at which the radius of the earths orbit subtends an angle of 1 arc sec b) The distance at which the radius of the earths orbit subtends an angle of 1 arc min c) 10 AU d) 4.6 ly 16) All of the following are reasons why it is warmer in the summer than it is in the winter here in Philadelphia, EXCEPT: (c) a) The rays of the sun are more vertical in summer b) The sunlight per unit area is greater in the summer c) The earth is closer to the sun in the summer d) The atmosphere absorbs and reflects more radiation in the winter 17) The changing orientation of the earth s axis of rotation is called (c) a) Rotation b) Procession c) Precession d) Declination e) Ascension 18) All of the following are reasons that total solar eclipses are rare, EXCEPT: (a) a) The moon has a much smaller angular size than the sun b) The moon s is inclined with respect to the plane of the earth s orbit c) The moon s shadow is very small when cast on the earth 19) Philadelphia can expect to experience a total solar eclipse about: (d) a) Once every hundred years b) Once every eighteen years c) Once a month d) Once every four hundred years e) Once every one thousand two hundred years 20) The notion that models of the solar system should be passed of the perfection of circles was first proposed by: (e) a) Ptolemy b) Copernicus c) Aristotle d) Aristarchus e) Plato 21) Aristotelian Physics is incorrect because: (b) a) For every action there is an equal and opposite reaction b) Objects in motion remain in motion in the absence of forces c) The sun is, in fact, at the center of the solar system d) Stellar parallax is observed e) The correct theory was proposed by Kepler

4 22) The relative distances of the earth, moon and sun were determined by: (a) a) Aristarchus b) Plato c) Ptolemy d) Kepler e) Brahe 23) Ptolemy s model of deferents and epicycles was so successful because: (e) a) It was favored by the church b) It made use of circles c) It predicted the positions of the planets d) It explained the retrograde motion of mars 24) Eratosthenes is best known for: (c) a) Predicting solar eclipses b) Collecting very accurate astronomical data c) Measuring the size of the earth d) Discovering the Analemma 25) Stellar Parallax is best defined as: (d) a) The motion of the stars due to the rotation of the earth b) The change in the relative positions of the stars due to the earth s changing axis of rotation c) The change in the positions of constellations during the seasons d) The change in the relative positions of the stars due to the earth s orbital motion 26) According to the Ptolemy model, the orbit of the planets and the sun from the center of the solar system outward is: (d) a) Sun-mercury-venus-earth-mars-jupiter-saturn b) Earth-sun-mercury-venus-mars-jupiter-saturn c) Earth-venus-mercury-sun-mars-jupiter-saturn d) Earth-mercury-venus-sun-mars-jupiter-saturn 27) In 1252, an effort to refine tables of data derived from Ptolemy s model was undertaken by: (a) a) Alfonso X b) Tycho Brahe c) Johannes Kepler d) The Catholic Church e) Martin Luther f) None of these 28) The principle known as Occam s razor may be stated as: (e) a) Models of the solar system should be based on the perfection of circles b) Models of the solar system are necessarily complex c) The motions of the planets around the sun must be governed by a rational physical law d) You re damned if you do; you re damned if you don t

5 29) The central idea of the Copernican Model is: (b) a) The orbits of the planets are ellipses b) The sun is at the center of the solar system c) Retrograde motion can not be explained d) Religion has no place in astronomy e) The fixed stars are much closer to earth than anyone expected 30) The single most important contribution of Tycho Brahe to astronomy was: (c) a) Observations of the moon s phases b) Mathematical models of higher precision than Ptolemy c) Collection of very accurate observational data d) Invention of the telescope e) Two words Bling, bling! 31) Of the following laws, which are attributed to Kepler: I: The Harmonic law, II: The law of Inertia, III: Law of Ellipses, IV: The law of Conic sections, V: The law of Areas, VI: The law of Retrograde Motion. (d) a) I, IV and VI b) I, II and IV c) III, IV and V d) I, III and V e) III and V only 32) Which of the following is NOT as consequence of Kepler s laws? (a) a) Planets move faster when they are at aphelion b) Angular momentum is conserved c) The radii of the planets orbits may be determined d) The eccentricity of an orbit is defined 33) Retrograde motion of mars is ultimately explained by: (c) a) The harmonic law b) The backward motion of mars on its epicycle c) The passing of mars by the earth during its orbit d) Stellar parallax 34) The value of the harmonic law constant k may be expressed as: (a) a) 1 AU 3 /yr 2 b) 1 km 3 /yr 2 c) 1 m 3 /s 2 d) 1 AU 2 /yr 3 35) The length of a year on mars may be determined by: (e) a) Using the harmonic law b) Using the law of areas c) Using the Analemma d) Timing the orbit of mars around the sun e) Observing the retrograde motion of mars

6 36) The phases of the moon derive their names from: (b) a) The appearance of the dark side b) The appearance of the light side c) The time when they are observed d) Arbitrary assignment 37) A full moon will rise at approximately: (b) a) 6am b) 6pm c) 12am d) 12pm e) The rise time will vary 38) An annular eclipse is caused by: (c) a) Refraction in the earth s atmosphere b) The varying size of the moons shadow c) The relative distances of the earth moon and sun d) Optical illusion 39) The earth is closest to the sun: (e) a) At the autumnal equinox b) At the vernal equinox c) At the summer solstice d) At the winter solstice 40) The line where the earth s equator cuts the celestial sphere is: (d) a) The ecliptic b) The tropic of cancer c) The baseline d) The celestial equator e) The celestial pole 41) The light-year is a measure of: (b) a) Time b) Distance c) Daylight hours in one year d) Orbital motion 42) The Analemma is caused by: (c) a) The rotation of the earth on its axis b) The precession of the earth on its axis c) The tilt of the earth on its axis d) The varying length of the day throughout the year 43) What two pieces of information are needed to determine the diameter of a far away object? (e) a) The celestial coordinates and angular size b) The right ascension and the angular size c) The declination and the angular size d) The right ascension and declination

7 44) The term universe is used by astronomers to mean: (a) a) The totality of all space, time, matter, and energy b) The volume enclosed by a sphere of furthest distance c) Everything that can be observed from earth d) The region above the earth s atmosphere 45) The angular size of the moon, as viewed from earth, is most nearly, (b) a) 1 b) 5 c) 10 d) 15 e) 20 46) Mercury and Venus are always are always observed to be: (b) a) Near each other b) No more than 47 from the sun c) Exhibiting retrograde motion d) In a crescent phase 47) Tycho Brahe was a supporter of the solar system model proposed by: (a) a) Himself b) Copernicus c) Kepler d) Ptolemy 48) During the dark ages: (c) a) European astronomy thrived b) Most astronomical observations were made by the Chinese c) The Arab world preserved and advanced astronomical knowledge d) Most of the know astronomy was lost. 49) Daily observations of the shadow of a stick placed vertically in the ground will reveal: (e) a) The analemma b) True north c) The length of the year d) The vernal and autumnal equinoxes 50) If the earth is considered to be roughly the size of a person s fist, the moon would be most nearly: (a) a) The size of a thumb 3 meters away b) The size of a fist 1 meter away c) The size of a thumb 1 meter away d) The size of a fist 20 meters away e) The size of a thumb 20 meters away