Astronomy: Planetary Revolutions, Solar System Models, and Stars - Prof. Harold Geller, Exams of Astronomy

Download Astronomy: Planetary Revolutions, Solar System Models, and Stars - Prof. Harold Geller and more Exams Astronomy in PDF only on Docsity! ASTRonomy 302 Examination #1 Fall 2008 ANSWERS I understand that this examination period goes from 12 PM through 1:15 PM, and that I may be required to stay in my seat for the entire period of time. Also, I have not received, nor given any aid, nor assistance, nor answers, nor questions to anyone else during this examination period. I understand that any violation of the GMU honor code will result in my being reported directly to the honor committee, without warning. I understand that any honor code violation can cause me to fail the course, be suspended, and/or be expelled from the university; and, it will automatically be entered into my official records. Name: _____________________ Print _____________________ Signature _____________________ Student ID _____________________ Date 1 The period of a planet revolving around the Sun can be found if we know its *A average distance from the Sun B density C mass D period of rotation E More than one of the above is needed. 2 At what latitude on Earth is the North Celestial Pole at your zenith? A the Arctic Circle B the equator *C the North Pole D the South Pole E there are many latitudes where this occurs 3 Galileo's observations of the phases of Venus helped convince him that A the Moon goes around the Earth B the Sun goes around the Earth C Venus goes around the Earth *D Venus goes around the Sun E Ptolemy's model of the solar system was correct 4 The angular distance of an object in the sky, above the observer's horizon is called its A azimuth *B altitude C declination D latitude E right ascension 5 The angular distance of an object in the sky above or below the Celestial Equator is called its A azimuth B altitude *C declination D latitude E right ascension 6 The ecliptic is defined as A the line passing from north to south directly overhead B the orbit of the Moon C the path of a star in the sky D the path of the Earth's north pole in the sky *E the path of the Sun in the sky 7 Which of the following statements about the Copernican solar system model is CORRECT? A it did away with the need for epicycles B it was the first time ever that the Sun was considered at the center of the solar system C it provided a physical explanation of why the planets moved *D it used uniform circular motion E all of the above are correct 8 Suppose you are a space shuttle astronaut taking a space walk. Your tether breaks and the jets on your backpack are out of fuel. How can you get back to the shuttle alive? A flap your arms B lean closer to the center of mass *C throw your backpack directly away from the shuttle D wait for gravity to pull you and the shuttle together E start spinning yourself 9 If the Earth's axis were not tilted with respect to its orbital plane, then A a mean solar day would be longer B a sidereal day would be longer C the tides would be much stronger *D there would be virtually no seasons E the period of revolution and rotation would be equal 10 What is the phase of the Moon at point 1 in the diagram? *A first quarter B full C new D third quarter E waning crescent 11 Tycho Brahe's main contribution to astronomy was his A calculation of the orbits of the planets B model of the solar system *C observations of the planets' positions D textbook on the solar system and its origin E collection of anecdotes about Galileo 26 Which letter is closest to the location of a red giant? A B *C D 27 A type-II supernova A occurs when a white dwarf's mass exceeds the Chandrasekhar limit B is the result of helium flash C is characterized by a spectrum that shows hydrogen lines D occurs when the iron core of a massive star collapses *E c and d 28 Which of the following statements are true about neutron stars? A Pulsars are pulsating neutron stars. B All neutron stars are pulsars. *C All pulsars are rotating neutron stars. D Neutron stars are made of degenerate electrons. E Neutron stars become black holes after a period of time. 29 Up to 90 percent of a star's mass can be thrown off in a supernova explosion. The remainder of the star will be a A black hole B neutron star C white dwarf *D more than one of the above is possible E none of the above is possible 30 Which represents the proper sequence for the development of a star to the Main Sequence? A Gas cloud, fragmentation, protostar, Hayashi Track, Kelvin-Helmholtz contraction, ignition, adjustment to Main Sequence. B Fragmentation, gas cloud, protostar, Kelvin-Helmholtz contraction, Hayashi Track, ignition, adjustment to Main Sequence. C Gas cloud, fragmentation, Kelvin-Helmholtz contraction, Hayashi Track, ignition, protostar, adjustment to Main Sequence. D Gas cloud, fragmentation, protostar, Kelvin-Helmholtz contraction, ignition, Hayashi Track, adjustment to Main Sequence. *E Gas cloud, fragmentation, protostar, Kelvin-Helmholtz contraction, Hayashi Track, ignition, adjustment to main sequence. 31 The mass of a single galaxy may be found by applying which of the following methods? A The double galaxy method. *B The rotation curve method. C The cluster method. D Any of the above methods will do. E None of the above methods help in determining mass of a galaxy. 32 A Hubble galaxy classification diagram is shown. Which of the labeled figures above represents an SBa galaxy? A 1 *B 2 C 3 D 4 E 5 33 Isotropy is defined as a characteristic of the universe in which A the universe looks the same at all epochs. B the universe looks the same from all locations over sufficiently great distances. *C the universe looks the same in all directions over sufficiently great distances. D all the above. E none of the above. 34 If galaxy A is sixteen times more distant than galaxy B, then according to the Hubble Law, galaxy A will recede at a velocity ___________ than galaxy B. *A 16 times faster B 8 times faster C 4 times faster D 2 times faster E 0.125 times faster 35 In the following diagram, the depiction on the LEFT can be considered to be: A isotropic, but not homogeneous *B homogeneous, but not isotropic C homogeneous and isotropic D neither homogeneous nor isotropic E none of the above 36 Given the following geometric possibilities of the universe, within which geometry do triangles contain less than 180 degrees? A Closed Geometry *B Open Geometry C Flat Geometry D Both Open and Closed Geometry E Both Flat and Closed Geometry 37 Which of the following was a consequence of the Einstein Special Theory of Relativity? A Events which are simultaneous to a stationary observer are simultaneous to a moving observer. *B Nothing can move faster than c, the speed of light in vacuum. C A stationary observer will see a moving clock running at the same rate. D A moving object will be stretched along its direction of motion. E All of the above are true. 38 The representation of gravity as a curvature of space similar to a flexible rubber sheet was first expressed in A Einstein's Special Theory of Relativity. *B Einstein's General Theory of Relativity. C Newton's Laws of Motion. D Newton's Law of Universal Gravitation. E Heisenberg's Uncertainty Principle. 39 The principle asserting the speed of light as a limiting velocity in nature, was first put forth as a basic principle in A Newton's Theory of Universal Gravitation. B Michelson-Morley Experiment. C Einstein's General Theory of Relativity. *D Einstein's Special Theory of Relativity. E Einstein's Theory of the Photoelectric Effect. 40 Albert and Marie are in different but identical spacecraft, traveling in opposite directions at 90% the speed of light. Albert looks out of his the window and watches Marie’s spacecraft pass his by. Which of the following statements is true about measurements he makes? A Marie’s spacecraft appears lighter in mass and longer in length. *B Marie’s spacecraft appears heavier in mass and shorter in length. C Marie’s spacecraft clock appears to be moving faster than Albert’s spacecraft. D Marie’s spacecraft appears the same in mass and the same in length. E None of the above statements are true. 41 Which of the following is true about the so called Twin Paradox? A It cannot be resolved by the General Theory of Relativity. *B It cannot be resolved by the Special Theory of Relativity. C It is a logical paradox. D It violates the laws of physics. E All of the above are true.