Download Answer - Brock physics

BROCK UNIVERSITY
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Test 1: April 2015
Course: ASTR 1P02, Section 2
Examination date: 20 April 2015
Time of Examination: 14:00 – 16:00
Number of pages: 18
Number of students: 883
Time limit: 2 hours
Instructor: S. D’Agostino
Answer all questions on the scantron sheet provided.
No aids are permitted except for a non-programmable calculator. Use or possession of unauthorized materials will automatically result in the award of a zero
grade for this examination.
Return both the exam script and your scantron sheet when you
leave the exam room.
Each question is worth 1 mark. Total number of marks: 100.
1. If the lifetime of Star A is significantly greater than the lifetime of Star B, then
(a) the mass of Star A is greater than the mass of Star B.
(b) * the mass of Star A is less than the mass of Star B.
(c) the two masses are about the same, because all stars have about the same mass.
(d) [There is no relation between the mass of a star and its lifetime.]
2. The youngest stars
(a) are always found living with older “grandparent” stars, until they are mature
enough to fend for themselves.
(b) are typically in regions of space where there is very little gas and dust.
(c) * are typically surrounded by clouds of gas and dust.
(d) are typically found in the centres of galaxies.
3. Dark nebulae emit significant amounts of
(a) * infrared radiation.
(b) ultraviolet radiation.
(c) dark energy.
(d) nebulinos.
4. Emission nebulae emit large amounts of
(a) * red light.
(b) blue light.
(c) green light.
(d) yellow light.
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5. Giant molecular clouds
(a) have been known to contain giant bean stalks.
(b) are regions of space in which white dwarfs become red dwarfs.
(c) * are regions of space in which stars form.
(d) frequently trigger supernovae explosions.
6. Giant molecular clouds
(a) typically contain giants who eat Englishmen.
(b) are typically uniform.
(c) * typically contain clumps.
(d) typically contain mostly carbon molecules.
7. The proton-proton chain
(a) is a famous song by Fleetwood Mac.
(b) is used to link stars on the H-R diagram.
(c) * is the major way that low-mass stars stars fuse hydrogen into helium.
(d) is the major way that high-mass stars stars fuse hydrogen into helium.
8. Hydrostatic equilibrium is the state of a star when it
(a) is a protostar.
(b) becomes a supernova.
(c) * is on the main sequence.
(d) [Stars are never in hydrostatic equilibrium because they continue to emit light.]
9. As fusion proceeds in the core of a star, the number of particles
temperature of the core must
to maintain core pressure.
(a) increases, increase
(b) increases, decrease
(c) * decreases, increase
(d) decreases, decrease
10. The helium flash is the onset of fusion of
(a) * helium into carbon
(b) hydrogen into helium
(c) helium into boron
(d) helium into beryllium
in the core of a star.
, and so the
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11. The remnant of a medium-mass star is
(a) * a white dwarf and a planetary nebula.
(b) a neutron star and a planetary nebula.
(c) a black hole and a planetary nebula.
(d) a pulsar and a planetary nebula.
12. The core of a white dwarf consists mainly of
(a) hydrogen and helium, with a smattering of heavy elements.
(b) an iron core, with concentric rings of lighter elements.
(c) primarily neutrons, covered by a thin layer of heavy elements.
(d) * carbon and oxygen.
13. Nuclear fusion takes place in a white dwarf mainly in
(a) its core.
(b) the region just outside the core (“helium flash”).
(c) near the surface, driven by electron degeneracy.
(d) * [Virtually no nuclear fusion occurs in a white dwarf.]
14. Planetary nebulae often appear approximately ring-like because
(a) they are formed in much the same way that cigarette-smokers blow smoke rings.
(b) strong magnetic fields cause jets of ejected material that align the nebulae into
rings.
(c) * they are approximately spherical shells, and only appear ring-like because of
our viewing perspective.
(d) they form in the same way as other planetary ring systems, such as the rings
around Saturn.
15. Star A and Star B are both white dwarfs, and therefore made of degenerate matter.
The mass of Star A is greater than the mass of Star B. The radius of Star A is
(a) * less than the radius of Star B.
(b) greater than the radius of Star B.
(c) about the same as the radius of Star B, because all white dwarfs have approximately the same radius.
(d) [It’s not possible to say, because there is no relation between the mass and radius
for a white dwarf.]
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16. A type Ia supernova occurs because of
(a) the core collapse of a high-mass star.
(b) the core collapse of a medium-mass star.
(c) * matter from a nearby star falling onto the surface of a white dwarf, becoming
compressed and heated, and eventually resulting in an explosion.
(d) matter from a nearby star falling onto the surface of a neutron star, becoming
compressed and heated, and eventually resulting in an explosion.
17. A type II supernova occurs because of
(a) * the core collapse of a high-mass star.
(b) the core collapse of a medium-mass star.
(c) matter from a nearby star falling onto the surface of a white dwarf, becoming
compressed and heated, and eventually resulting in an explosion.
(d) matter from a nearby star falling onto the surface of a neutron star, becoming
compressed and heated, and eventually resulting in an explosion.
18. Distances to the most distant galaxies are determined using
(a) the method of standard candelabras.
(b) * Type Ia supernovae.
(c) Type II supernovae.
(d) the method of planetary nebulae.
19. A pulsar is a rapidly rotating
(a) white dwarf.
(b) * neutron star.
(c) black hole.
(d) quasar.
20. Neutron stars typically spin at a rate that is
(a) * much faster than regular stars.
(b) about the same as regular stars.
(c) much slower than regular stars.
(d) [It depends on the neutron star; there is a very wide range of rotational speeds.]
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21. The escape velocity from a black hole is
(a) * greater than the speed of light.
(b) slightly less than the speed of light (no speed can be greater than the speed of
light).
(c) equal to the speed of light (right at the event horizon).
(d) [Black holes do not have escape velocities.]
22. The idea that the Milky Way galaxy is disk-shaped was first proposed by
(a) Aristotle.
(b) Galileo Galilei.
(c) Johannes Kepler and Tycho Brahe.
(d) * Thomas Wright and Immanuel Kant.
23. Our location in the Milky Way galaxy was first established by
(a) Fred Hoyle.
(b) Edwin Hubble.
(c) * Harlow Shapley.
(d) Vesto Slipher.
(e) Fritz Zwicky.
24. Our location in the Milky Way galaxy was first determined using measurements of
distances to
(a) open clusters
(b) * globular clusters
(c) type Ia supernovae
(d) type II supernovae
25. The disk of the Milky Way contains
(a) * stars, star clusters, gas and dust.
(b) stars, star clusters, but no gas and dust.
(c) stars, gas and dust, but no star clusters.
(d) stars, no gas and dust, and no star clusters.
(e) gas and dust, but no stars or star clusters.
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26. The halo of the Milky Way contains
(a) stars, star clusters, gas and dust.
(b) * stars, star clusters, but no gas and dust.
(c) stars, gas and dust, but no star clusters.
(d) stars, no gas and dust, and no star clusters.
(e) gas and dust, but no stars or star clusters.
27. The stars in the bulge of the Milky Way are similar to the stars in the halo, but the
bulge also contains
(a) * some hot, luminous stars.
(b) no very massive stars.
(c) spiral arms.
(d) no very young stars.
28. Associations and open clusters of hot, luminous stars are found in the
of the Milky Way.
(a) bulge
(b) halo
(c) nucleus
(d) * spiral arms
29. “Rotation curves” for stars at various positions in the Milky Way, first measured by
Vera Rubin, do not match observed luminous matter in the galaxy. This is strong
evidence for the presence of
(a) the gyre in the constellation Pisces, which contains an enormous amount of plastic
garbage.
(b) * dark matter in the Milky Way.
(c) a giant black hole at the centre of the Milky Way.
(d) an enormous number of neutrinos streaming through the Milky Way.
30. A MACHO is
(a) an overly-aggressive dude who is full of himself and has no empathy.
(b) a satellite deployed to detect giant black holes.
(c) a multiple-aperture confocal holistic observatory.
(d) * a massive astrophysical compact halo object.
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31. A WIMP is
(a) a cowardly dude who doesn’t stand up for himself.
(b) a satellite deployed to detect cosmic rays from the galactic nucleus.
(c) a well-tempered interferometric molecular probe.
(d) * a weakly-interacting massive particle.
32. Elliptical galaxies contain mostly
(a) Population I stars and tend to be red.
(b) Population I stars and tend to be blue.
(c) * Population II stars and tend to be red.
(d) Population II stars and tend to be blue.
33. The mass of every observed elliptical galaxy
(a) is more than the mass of the Milky Way galaxy.
(b) is less than the mass of the Milky Way galaxy.
(c) * might be more or less than the mass of the Milky Way galaxy.
34. Lenticular (S0) galaxies
(a) have very large nuclei and very large spiral arms.
(b) * have very large nuclei and barely visible spiral arms.
(c) have very small nuclei and very large spiral arms.
(d) have very small nuclei and barely visible spiral arms.
35. An irregular galaxy
(a) is badly in need of laxatives.
(b) is looked down-upon by all the regular galaxies in the neighbourhood.
(c) * contains a chaotic mix of gas and dust with no obvious nucleus and no spiral
arms.
(d) contains a chaotic mix of constellations, where the stars in each constellation do
not conform to any recognizable patterns.
36. The number of elliptical galaxies we observe is
we observe.
(a) about twice
(b) about 100 times
(c) * about half
(d) about 1/100th
the number of spiral galaxies
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37. Superclusters
(a) are the top-ranked galaxy clusters.
(b) are clusters that win more than one galactic Super Bowl.
(c) are extremely large galaxy clusters.
(d) * are formed of clusters of galaxies grouped together.
38. Olbers’s paradox states that if you make a few simple assumptions then you can conclude that
(a) * the night sky should not be dark.
(b) the Sun should have died long ago.
(c) the solar system should be considerably smaller.
(d) the Milky Way should contain much more dust than it actually has.
39. A simple resolution to Olbers’s paradox, suggested by the poet Edgar Allan Poe, and
later generally accepted after much scientific discussion, is that
(a) * the age of the universe is finite.
(b) interstellar dust blocks light from distant stars.
(c) light from very distant stars gradually loses energy over its long journey (the
“tired-light” hypothesis).
(d) there are a lot fewer stars than astronomers say there are, an obvious error that
mainstream astronomers will not admit to making.
40. The Big Bang theory explains in detail
(a) * how the universe was in a very hot dense state in the past and has expanded
ever since.
(b) how type Ia supernovae explode.
(c) how type II supernovae explode.
(d) how quasars manage to emit such intense radiation.
41. The Hubble time
(a) like Miller time, is a sort of “happy hour” for astronomers.
(b) gives an approximation for the age of the oldest stars.
(c) gives an approximation for the age of the solar system.
(d) * gives an approximation for the age of the universe.
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42. There is plenty of good evidence for the Big Bang theory, including the abundance of
(a)
(b)
(c)
(d)
heavy elements in type Ia supernova explosions.
electromagnetic radiation in type II supernova explosions.
neutrinos in the cosmic microwave background radiation.
* hydrogen and helium in the universe.
43. Astronomers made a startling observation in 1998, that about 4 billion to 5 billion
years ago
(a)
(b)
(c)
(d)
the rate of energy production in stars began to decrease.
the emission of radio waves from Seyfert galaxies began to increase.
the average temperature of the universe suddenly decreased.
* the expansion of the universe began to accelerate.
44. The Jovian planets are typically
(a)
(b)
(c)
(d)
much more jolly than the terrestrial planets.
* much larger than the terrestrial planets.
about the same sizes as the terrestrial planets.
much smaller than the terrestrial planets.
45. The Jovian planets have orbits that are typically
(a)
(b)
(c)
(d)
closer to Mount Olympus than the terrestrial planets.
* farther from the Sun than the terrestrial planets.
about the same distances from the Sun as the terrestrial planets.
closer to the Sun than the terrestrial planets.
46. Pluto is no longer considered to be a planet because
(a)
(b)
(c)
(d)
it got into a big personal disagreement with the President of the Planet Club.
it is not massive enough to be approximately spherical.
it does not actually revolve around the Sun, but rather orbits Neptune.
* it has not “cleared its orbit;” that is, it is not the only body of its size at its
approximate distance from the Sun.
47. Kepler’s first law states that
(a)
(b)
(c)
(d)
“Tycho Brahe should keep his nose out of my business.”
planets closer to the Sun have smaller masses than planets farther from the Sun.
planets with a larger diameter have a larger density.
the distances between adjacent planets is proportional to the angular momentum
of each planet.
(e) * the orbit of each planet is an ellipse, and the Sun is at one focus of the ellipse.
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48. In our solar system, planetary orbits
(a) take turns on the solar system’s periphery, like emperor penguins in Antarctica.
(b) * are nearly all in the same plane.
(c) are chaotic, and do not lie nearly in the same plane.
(d) are nearly all in the same cone.
49. Kepler’s third law relates a planet’s
to its
.
(a) prison sentence, size of its grow-op
(b) * distance from the Sun, orbital period
(c) diameter, orbital period
(d) distance from the Sun, rotational period
(e) diameter, rotational period
50. The planet in our solar system with the smallest density is
(a) Jupiter.
(b) * Saturn.
(c) Uranus.
(d) Neptune.
51. The planet in our solar system that is closest to the Sun is
(a) * Mercury.
(b) Venus.
(c) Earth.
(d) Mars.
52. The planet in our solar system that is farthest from the Sun is
(a) Jupiter.
(b) Saturn.
(c) Uranus.
(d) * Neptune.
53. Which planet has the highest reflectivity (albedo)?
(a) Mercury
(b) * Venus
(c) Earth
(d) Mars
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54. Which planet has the highest surface temperature?
(a) Mercury
(b) * Venus
(c) Earth
(d) Mars
55. Which planet has the highest surface atmospheric pressure?
(a) Mercury
(b) * Venus
(c) Earth
(d) Mars
56. The age of the solar system is about
(a) 4.6 thousand years.
(b) 4.6 million years.
(c) * 4.6 billion years.
(d) 4.6 trillion years.
57. The age of the Earth is determined by
(a) asking the Earth’s mother when it was born.
(b) looking up the online records in Encyclopedia Galactica.
(c) * radioactive dating of rocks and crystals.
(d) carbon-14 dating of rocks and crystals.
58. Some evidence of intense bombardment in the solar system by leftover debris is
(a) discarded debris in garbage dumps all over the solar system.
(b) many impact craters on all planets and nearly all satellites.
(c) many impact craters on Jovian planets and nearly all satellites.
(d) * many impact craters on terrestrial planets and nearly all satellites.
59. Impact craters differ from volcanic craters because impact craters
(a) have no central peak.
(b) * have floors that are lower than surrounding terrain.
(c) are filled with rubble.
(d) have much larger magnetic fields.
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60. The structure of the Earth’s core is studied by analyzing
(a)
(b)
(c)
(d)
images obtained by sending fibre optic cables down deep mine shafts.
core samples obtained from deep drilling.
boring tunnels deep beneath the Earth’s surface.
* the propagation of earthquake waves.
61. The theory of plate tectonics (continental drift) was proposed by
(a)
(b)
(c)
(d)
Charles Darwin in 1868.
* Alfred Wegener in 1912.
Arno Penzias and Robert Wilson in 1964.
William Pangea in 1977.
62. The theory of continental drift proposes that
(a) the continents drift very gradually clockwise, in the opposite direction of the
Earth’s rotation.
(b) the continents drift very gradually counter-clockwise, in the same direction as the
Earth’s rotation.
(c) the continents drift very gradually towards the poles and away from the equator.
(d) * long ago the continents were very close together, and they have been gradually
drifting apart ever since.
63. Where major continental plates meet, one finds an increase in
(a)
(b)
(c)
(d)
continental dishes, continental silverware, and continental table cloths.
plant life.
the vertical component of the Earth’s magnetic field.
* volcanic activity and earthquakes.
64. More volcanoes are found on
(a)
(b)
(c)
(d)
than on any other planet.
Mercury
* Venus
Earth
Mars
65. Besides a planet’s primary atmosphere, another main source of gases in the atmospheres
of most planets in the solar system is
(a)
(b)
(c)
(d)
condensation of gases from passing comets.
cellular respiration of living creatures.
photosynthesis of green plants.
* volcanic activity.
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66. The planets that still have much of their primary atmospheres are
(a) only Jupiter.
(b) only Earth.
(c) all terrestrial planets.
(d) * all Jovian planets.
67. The most abundant gas in the atmosphere of Venus is
(a) sulfuric acid.
(b) oxygen.
(c) nitrogen.
(d) * carbon dioxide.
68. A planet can lose its atmosphere if
(a) the atmosphere goes walking about in an unfamiliar neighbourhood.
(b) * its surface is too hot.
(c) its surface is too cold.
(d) the rate of chemical reactions in the atmosphere is too large.
(e) the rate of chemical reactions in the atmosphere is too small.
69. The temperature of a planet is determined primarily by the planet’s
(a) * distance from the Sun and its reflectivity.
(b) distance from the Sun and its diameter.
(c) diameter and reflectivity.
(d) diameter and mass.
70. Mercury’s atmosphere
(a) * is almost nonexistent.
(b) is formed primarily from noble gases.
(c) contains mainly hydrogen.
(d) contains mainly nitrogen.
71. The most abundant gas in Earth’s atmosphere is
(a) * nitrogen.
(b) oxygen.
(c) carbon dioxide.
(d) hydrogen.
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72. Venus has a much higher surface temperature than Earth, primarily because
(a) Venus is much closer to the Sun.
(b) Venus has a much higher reflectivity (albedo).
(c) Venus has a much lower reflectivity (albedo).
(d) * of the greenhouse effect.
73. The concentration of oxygen in the Earth’s atmosphere increased dramatically about
2 billion years ago because
(a) the amount of hot air in the atmosphere increased dramatically thanks to the
evolution of Donald Trump.
(b) the Earth’s surface temperature increased dramatically.
(c) the Earth experienced the Maunder minimum and the “little ice age.”
(d) * of the appearance of blue-green algae.
74. The atmosphere of Mars is
(a) much denser than the atmosphere of Earth, because Mars is colder.
(b) much denser than the atmosphere of Earth, because Mars has a smaller surface
gravity
(c) much less dense than the atmosphere of Earth, because Mars is colder.
(d) * much less dense than the atmosphere of Earth, because Mars has a smaller
surface gravity.
75. Tidal forces exerted by the Moon on the Earth cause
(a) a tidal bulge on the side of the Earth facing towards the Moon.
(b) a tidal bulge on the side of the Earth facing away from the Moon.
(c) * two tidal bulges, one each on the sides of the Earth facing towards and away
from the Moon.
(d) [The Moon does not exert tidal forces on the Earth.]
76. On Earth there is a high tide and a low tide approximately
(a) once per day.
(b) * twice per day.
(c) once per month.
(d) twice per month.
77. Tidal forces cause the Earth’s rotational rate to
century.
(a) increase
(b) * decrease
by about 0.002 seconds per
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78. Tidal forces cause the Moon (and many other satellites in the solar system) to have
synchronous rotation. This means that the Moon’s rotational period is synchronized
with
(a) the Earth’s rotational period.
(b) * the Moon’s orbital period.
(c) the Earth’s orbital period.
(d) the Moon’s precessional period.
(e) the Earth’s precessional period.
79. Planetary rings are found around
(a) all planets in our solar system.
(b) just Saturn.
(c) just Jupiter and Saturn.
(d) * Jupiter, Saturn, Uranus, and Neptune.
80. The rings around the planet Saturn have gaps, the largest of which is named after the
astronomer
(a) Brahe.
(b) * Cassini.
(c) Copernicus.
(d) Galileo.
(e) Kepler.
81. The rings of Saturn were discovered by the astronomer
(a) Brahe.
(b) Cassini.
(c) Copernicus.
(d) * Galileo.
(e) Kepler.
82. The rings of Jupiter were discovered by
(a) Ringo Starr.
(b) Richard Starkey, Jr.
(c) * the Voyager 1 space probe.
(d) the Hubble space telescope.
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83. The rings of Saturn are about
(a) 1 m thick.
(b) 10 m thick.
(c) * 100 m thick.
(d) 1000 m thick.
84. The gaps in the rings of Saturn are caused by
(a) several satellites of Saturn playing “ring around the Rosie.”
(b) tidal forces due to the satellite Mimas.
(c) * resonant gravitational attraction from the satellite Mimas.
(d) local repulsions due to clumps of dark energy.
85. Comets
(a) is the name of Hamilton’s proposed new NHL franchise.
(b) a brand of household sink and counter-top cleaners.
(c) are flashes of light that appear for just a second or two as they rapidly move
across the sky.
(d) * slowly shift their position in the sky from night to night and remain visible for
a few days up to a few months.
86. The nucleus of a comet resembles a “dirty snowball,” and is made up of water ice,
small amounts of
(a) metals, and frozen triple-mix, with a sprinkling of sheep manure.
(b) stones, and frozen ozone, pentane, and carbon monoxide.
(c) silicates, and frozen ammonia, butane, and carbon tetrachloride.
(d) * rocks, and frozen ammonia, methane, and carbon dioxide.
87. The coma of a comet is a glowing ball of gas, which for most comets has a diameter
between
(a) 100 km and 1,000 km.
(b) 1,000 km and 10,000 km.
(c) 10,000 km and 100,000 km.
(d) * 100,000 km and 1,000,000 km.
88. The orbits of most comets are
(a) in the plane of the ecliptic.
(b) * not in the plane of the ecliptic.
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89. Most periodic and short-period comets originate in
(a) the small and large Magellanic clouds.
(b) the Oort cloud.
(c) the asteroid belt.
(d) * the Kuiper belt.
90. The largest asteroid in the solar system is
(a) Apollo.
(b) * Ceres.
(c) Eris.
(d) Trojan.
91. Most asteroids in the solar system are found in the asteroid belt, which lies
(a) * between the orbits of Mars and Jupiter.
(b) between the orbits of Jupiter and Saturn.
(c) on the edge of the Kuiper belt.
(d) towards the outside of the Oort cloud.
92. Most asteroids have orbital planes that are
(a) * near the ecliptic.
(b) near the celestial equator.
(c) near the celestial poles.
(d) near the celestial antipodes.
93. Trojan asteroids have orbits that are
(a) highly elliptical and cross Earth’s orbit.
(b) nearly circular and cross Earth’s orbit.
(c) * near Jupiter’s orbit, and about 60◦ ahead of and behind Jupiter.
(d) found mainly in the Kuiper belt.
94. Smaller asteroids tend to have
(a) * irregular shapes.
(b) highly spherical shapes.
(c) conical shapes.
(d) cylindrical shapes.
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95. The Kirkwood gaps are
(a) spaces between Mr. Kirkwood’s teeth, because his parents couldn’t afford orthodontics.
(b) * areas in the asteroid belt where there are relatively few asteroids.
(c) areas in the rings of Saturn where there is relatively little debris.
(d) areas in the atmosphere of Jupiter where there is relatively little ammonia wind.
96. The majority of asteroids are
(a) dazed and confused.
(b) * C-asteroids.
(c) M-asteroids.
(d) S-asteroids.
97. C-asteroids are made up of
(a) stony substances that were birthed by C-section.
(b) clusters of stones bonded together with cement-like agents.
(c) substances formed in the carboniferous era of the universe.
(d) * silicates mixed with dark carbon compounds.
98. M-asteroids are made up of
(a) mud-like substances, bonded together by the extreme cold of outer space.
(b) * metals such as nickel and iron.
(c) fragments broken off when the planet Mars formed.
(d) re-purposed meteoroids.
99. S-asteroids are made up of
(a) sandy materials bonded together with ices of gases such as ammonia and methane.
(b) sulfur compounds.
(c) sedimentary rocky materials.
(d) * silicates.
100. Solid objects that are smaller than asteroids and orbit the Sun are called
(a) meteors.
(b) meteorites.
(c) * meteoroids.
(d) meteorinos.