Exam 4 (practice) - Astro 001 unit test. answers same as the exam. Multiple versions of the exam. PDF

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Astro 001 unit test. answers same as the exam. Multiple versions of the exam....

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Points Awarded Points Missed Percentage

48 2 96%

1. What element is only produced in a supernova explosion? A. B. C. D. E.

oxygen iron gold hydrogen carbon Points Earned: 0/1 Correct Answer: Your Response:

2. Which of the following are flavors of quarks? A. B. C. D. E.

leptons and antileptons charge and mass top and up blue and green baryons and antibaryons Points Earned: 1/1 Correct Answer: Your Response:

3. Which of the following is thought to have to do with producing a 1 minute long gamma-ray burst? A. B. C. D. E.

a supernova dark matter a planetary nebula a quasar dark energy Points Earned: 1/1 Correct Answer: Your Response:

4. Which is true about cold dark matter? A. Cold dark matter exists only within planets and stars but not in other parts of galaxies or intergalactic space. B. Cold dark matter particles travel faster than the speed of light. C. Cold dark matter emits X-rays, but no other forms of radiation.

D. Cold dark matter particles travel more slowly than hot dark matter particles. E. Cold dark matter interacts strongly with ordinary baryonic matter via the strong force. Points Earned: 1/1 Correct Answer: Your Response: 5. How might a nearby neighbor change the shape of this galaxy? A. It might obliterate all life in that galaxy because of collisions between different planetary systems in the merger of the two galaxies. B. A merger with the neighbor might tighten the spiral arms and lead to a shrinking of the bulge component. C. It might make the disk of the galaxy thinner and the halo rounder. D. Small whirlpools might form in the disk of the spiral and the gas and stars would fall into them, leading to the disappearance of the disk. E. The merger of two spiral galaxies may give rise to an elliptical galaxy. Points Earned: 1/1 Correct Answer: Your Response: 6. Galaxy A is 300 Mpc from Galaxy B. Hubble's Law says that V=H 0 x D. About how fast is Galaxy A receding from the perspective of Galaxy B? Use a value of 75 km/s/Mpc for Hubble's constant. A. B. C. D. E.

225 km/s 30000 km/s 75 km/s 22500 km/s 15000 km/s Points Earned: 1/1 Correct Answer: Your Response:

7. How many galaxies are there in the part of the universe we can observe? A. B. C. D. E.

20,000-50,000. 100,000-300,000. 50-100 billion. 50-100 million. About 10,000. Points Earned: 1/1 Correct Answer: Your Response:

8. In the symbol for the Hubble type of a galaxy, SBc, the "B" denotes A. B. C. D. E.

the presence of a bar a large bulge component loosely wound spiral arms the presence of a ring tightly wound spiral arms Points Earned: 1/1 Correct Answer: Your Response:

9. Name the rapidly rotating disk at the center of the galaxy spinning around the black hole. A. B. C. D. E.

Acceleration disk. Galactic circular storm. Compaction zone. Convection cell. Accretion disk. Points Earned: 1/1 Correct Answer: Your Response: 10. Where do we observe black holes? A. B. C. D. E.

In orbit around stars in binary systems. In the center of the Milky Way Galaxy. In the centers of elliptical galaxies. In quasars. All of the above. Points Earned: 1/1 Correct Answer: Your Response:

11. What is the mass of the supermassive black hole in the center of the Andromeda galaxy? A. B. C. D. E.

10 times the mass of our Sun. 5000 billion times the mass of our Sun 400 billion times the mass of our Sun 30 million times the mass of our Sun 20 thousand times the mass of our Sun. Points Earned: 1/1 Correct Answer:

Your Response: 12. Which of the following areas have the most massive black holes (those with the highest masses)? A. B. C. D. E.

where a massive star has died in spiral galaxy halos in the outer halos of elliptical galaxies in X-ray binary stars in the centers of spiral galaxies Points Earned: 1/1 Correct Answer: Your Response:

13. How do astronomers measure the mass of a supermassive black hole? A. B. C. D. E.

by comparing its apparent magnitude to its absolute brightness using the formula E = mc2 by measuring its parallax by comparing its X-ray luminosity to its radio luminosity by measuring the speed at which stars move in its vicinity Points Earned: 1/1 Correct Answer: Your Response:

14. Which of the following are flavors of quarks? A. B. C. D. E.

Blue and green. Charge and mass. Leptons and antileptons. Baryons and antibaryons. Up and top. Points Earned: 1/1 Correct Answer: Your Response:

15. The universe formed Helium nuclei in a process called nucleosynthesis. At that time, what fraction of the mass was converted to Helium nuclei (2 protons and 2 neutrons)? A. B. C. D. E.

2 percent 50 percent 25 percent 99 percent 1 percent Points Earned: 1/1

Correct Answer: Your Response: 16. What is exchanged between different particles in order to make the forces work? A. B. C. D. E.

quarks leptons bosons baryons electrons Points Earned: 1/1 Correct Answer: Your Response:

17. Which is a reason that we know dark energy is a major component of the universe? A. Supernovae would not occur without dark energy. B. Dark energy is needed in order that light can escape from supermassive black holes. C. The universe is flat and regular matter doesn't contribute enough energy density. D. The gravity due to regular matter in the universe would have started it contracting again by now without dark energy. E. The universe would not be 2.7 degrees Kelvin today without dark energy. Points Earned: 1/1 Correct Answer: Your Response: 18. When examining a spectrum of a particular galaxy, an astronomer notices that the spectral lines are shifted toward shorter wavelengths. What does this mean? A. B. C. D. E.

the entire Universe is contracting the element Helium is present in that galaxy the galaxy is rotating very rapidly the galaxy is moving away from us the galaxy is very likely to be one of the nearest galaxies to the Milky Way Points Earned: 1/1 Correct Answer: Your Response:

19. Why can't we see back the whole way to the Big Bang? A. Radiation is blueshifted out of the visible range. B. Not enough photons were produced.

C. Our telescopes could never be powerful enough. D. The radiation scatters off matter frequently so the Universe is opaque. E. It would take too long for light to travel that far. Points Earned: 1/1 Correct Answer: Your Response: 20. Lee Smolin suggests that a new universe is born inside A. B. C. D. E.

every neutron star every star every universe every supernova every black hole Points Earned: 1/1 Correct Answer: Your Response:

21. Which constellation is this? A. B. C. D. E.

Cepheus, the King Draco, the Dragon Pegasus, the Winged Horse Andromeda, the Princess Orion, the Hunter Points Earned: 1/1 Correct Answer:

Your Response: 22. Compared to spiral galaxies, elliptical galaxies have... A. B. C. D. E.

...more gas, more dust, and less new star formation. ...less gas, more dust, and more new star formation. ...less gas, less dust, and more new star formation. ...more gas, more dust, and more new star formation. ...less gas, less dust, and less new star formation. Points Earned: 1/1 Correct Answer: Your Response:

23. Why was it important to have a "boring" patch of sky for the Hubble Deep Field? A. To minimize the number of objects in the view that were local to our own galaxy. B. To first take a "flat field" for use in comparison to a more interesting part of the sky. C. To avoid catching a comet or asteroid that could end up a blur streak across the entire image. D. To prevent the Hubble Space Telescope overheating from bright light sources. E. Honoring the memory of Edwin Hubble, who first searched this same part of space. Points Earned: 1/1 Correct Answer: Your Response: 24. A standard candle is A. a star that has unpredictable bursts of brightness followed by constant phases B. an easily recognizable astronomical object whose absolute brightness is confidently known C. a source of light that orbits the Earth in the Hubble Space Telescope and is used to calibrate telescopes on Earth D. a unit of luminosity used to measure the apparent brightness of distant objects E. a type of spectrograph used to measure the redshift or blueshift of a spectral line Points Earned: 0/1 Correct Answer: Your Response: 25. The few individual stars that are seen in the Hubble Deep Field image A. are actually distant quasars. B. are located in galaxies near the edge of the observable universe. C. are the main targets for our observations of that region of the sky.

D. are stars in our own Milky Way galaxy. E. are in the nearby Andromeda galaxy. Points Earned: 1/1 Correct Answer: Your Response: 26. Which is the smallest? A. B. C. D. E.

The distance from the Sun to its nearest neighboring star The distance from the Sun to the Andromeda Galaxy The distance from the Sun to the Virgo cluster of galaxies The distance from the Sun to the center of the Milky Way Galaxy The Solar System. Points Earned: 1/1 Correct Answer: Your Response:

27. Which statement about spiral galaxies is FALSE? A. B. C. D. E.

their disks rotate at more than 100 kilometers per second most of their star formation occurs in the spiral arms a type "a" spiral has a large bulge compared to a type "c" spiral a merger of two spiral galaxies may give rise to an elliptical galaxy a type "c" spiral has tight, smooth arms Points Earned: 1/1 Correct Answer: Your Response:

28. If a galaxy is moving away from us the wavelength of the light it emits will be A. B. C. D. E.

increased. blueshifted. unaffected. distorted. decreased. Points Earned: 1/1 Correct Answer: Your Response:

29. Which one of the following is TRUE? A. Irregular galaxies rarely have star formation taking place in them. B. Most galaxies appear to be approaching the Milky Way Galaxy.

C. Most elliptical galaxies contain only young stars. D. Smaller galaxies called dwarf galaxies tend to be found around larger galaxies like the Milky Way. E. Galaxy collisions destroy most of the stars in the galaxies involved. Points Earned: 1/1 Correct Answer: Your Response: 30. How many types of fundamental particles are there in the Universe and how many dominate on Earth? A. B. C. D. E.

About 30 with 3 dominant More than a million with 3 dominant About 300 with 30 dominant About 300 with 3 dominant About 30 with 15 dominant Points Earned: 1/1 Correct Answer: Your Response:

31. About how many dots are seen in the Hubble Deep Field image, just within that image? What are the dots seen in the Hubble Deep Field? A. B. C. D. E.

3000 galaxies. 3000 stars. 3 million galaxies. 100 galaxies. 3 million stars. Points Earned: 1/1 Correct Answer: Your Response:

32. An up quark has charge +2/3, a down quark has charge -1/3, and a strange quark has charge -1/3. The Delta- particle is formed by a combination of three down quarks. What is its charge? A. B. C. D. E.

+1/3 -1 0 1 -1/3 Points Earned: 1/1 Correct Answer:

Your Response:

33. Which constellation is this? A. B. C. D. E.

Draco, the Dragon Orion, the Hunter Cepheus, the King Pegasus, the Winged Horse Andromeda, the Princess Points Earned: 1/1 Correct Answer: Your Response:

34. An up quark has charge +2/3, a down quark has charge -1/3, and a strange quark has charge -1/3. The Lambda0 particle is formed by a combination of an up, a down, and a strange quark. What is its charge? A. B. C. D. E.

0 1 +2/3 -2/3 -1 Points Earned: 1/1 Correct Answer: Your Response:

35. What is the difference between an E0 and an E7 galaxy?

A. B. C. D. E.

The E7 has an oval shape and the E0 is circular. The E7 has a larger disk than the E0. There is no such thing as an E0 galaxy. The E7 has a circular shape and E0 is oval. The E7 has a smaller disk than the E0. Points Earned: 1/1 Correct Answer: Your Response:

36. What is the temperature of the universe at present? A. B. C. D. E.

about 10,000 degrees Kelvin about 300 degrees Kelvin about 2.7 degrees Kelvin about 1 million degrees Kelvin exactly 0 degrees Kelvin - absolute zero Points Earned: 1/1 Correct Answer: Your Response:

37. Galaxy A receding from Galaxy B at a velocity of 75000 km/s, from the perspective of Galaxy B. Hubble's Law says that V=H0 x D. About how far is Galaxy A from Galaxy B? Use a value of 75 km/s/Mpc for Hubble's constant. A. B. C. D. E.

50000 Mpc 100 Mpc 500,000 Mpc 5000 Mpc 1000 Mpc Points Earned: 1/1 Correct Answer: Your Response:

38. If the objects seen in the past are galaxies, how might they have changed? A. B. C. D. E.

Galaxies would have had less star formation in the past than at present. There were more ellipticals in the past and would be spirals at present. Things would have had a larger mass in the past than at present. They would have been destroyed by supernovae explosions by the present time. The galaxies were more irregular and patchy in the past than they are at present. Points Earned: 1/1

Correct Answer: Your Response: 39. Which of the following is TRUE? A. We see distant galaxies as they were billions or even tens of billions of years ago. B. We measure a redshift for roughly half of the galaxies that we observe, and for the others we measure a blueshift. C. It is possible for galaxies that are very distant to actually move through space at a speed several times the speed of light. D. A redshift occurs when a photon loses energy and slows down as it moves through space. E. The center of the universe is located at a point about 200 Mpc from us in the center of a cluster of galaxies. Points Earned: 1/1 Correct Answer: Your Response: 40. What do astronomer's mean when they say that Earth is not in a special spot? All space is expanding so Hubble's law would apply around all galaxies. The Big Bang explosion sent all material blasting away from the Earth. Hubble measured the expansion law from the Moon, not from the Earth. Hubble's law applies to some galaxies but not to others, so many planets besides Earth have their own Hubble's law. E. The Sun is at the center of the universe, but the Earth is not.

A. B. C. D.

Points Earned: 1/1 Correct Answer: Your Response: 41. Among these choices, which is the last thing that happens in the history of the universe? A. B. C. D. E.

formation of nuclei of helium the Planck time before which all four forces are unified inflationary expansion quarks binding together to form protons and neutrons binding of electrons to nuclei Points Earned: 1/1 Correct Answer: Your Response:

42. A parallel universe is

A. B. C. D. E.

another universe that exists separate from the space of our universe. a universe in which parallel light beams remain parallel. an open universe. a closed universe. a universe in which events occur in a logical order. Points Earned: 1/1 Correct Answer: Your Response:

43. Which of the following statements is definitely FALSE? A. New universes may break off from ours as it expands. B. String theory suggests that extra dimensions may exist beyond our three known spatial dimensions and time. C. Universes with the largest number of black holes are favored in the theory of natural selection of universes. D. There is an absence of space beyond the boundaries of our observable universe. E. There is a theory of quantum mechanics in which new universes split from ours at every random event. Points Earned: 1/1 Correct Answer: Your Response: 44. What is an SBc galaxy? A. B. C. D. E.

An unbarred spiral with tight, smooth spiral arms. A barred spiral with a large bulge. A compact spiral galaxy that is nearly featureless like an elliptical. A compact spiral with spiral arms in between loose and tight. A barred spiral with loose, lumpy spiral arms. Points Earned: 1/1 Correct Answer: Your Response:

45. Does the existence of quasars imply that radiation can escape a black hole? A. Yes, radiation can escape because the mass of a photon is zero. B. Quasars have nothing to do with black holes. C. No, the emission of radiation occurs before material falls in through the event horizon. D. Yes, the laws of physics break down so that material travels faster than the speed of light near quasars. E. Quasars do not produce radiation of any sort, so there is no contradiction. Points Earned: 1/1

Correct Answer: Your Response: 46. The hypernova model of the collapse of the core of a massive star may describe A. B. C. D. E.

the gravitational collapse of a protostar prior to the main sequence phase the feeding of material into a quasar a neutron star a relatively long gamma ray burst a black hole Points Earned: 1/1 Correct Answer: Your Response:

47. Which of the following makes a meson? A. B. C. D. E.

two down quarks and an anti-up quark a photon and a graviton three up quarks an up quark and an anti-down quark a charm quark and a strange quark Points Earned: 1/1 Correct Answer: Your Response:

48. Why can't we see dark matter? A. B. C. D. E.

Because it doesn't exist. It emits only infrared radiation and X-rays and not optical light. All of it is too far away. It doesn't emit radiation of any sort. It is blocked by dust lanes in galaxies. Points Earned: 1/1 Correct Answer: Your Response:

49. What fraction of the energy density of the universe consists of dark matter? A. B. C. D. E.

99 percent 75 percent 1 percent 4 percent 21 percent Points Earned: 1/1

Correct Answer: Your Response: 50. How many times smaller are the tiniest particles that we know about than the size of the Earth? A. about 1025 times smaller B. about 10 times smaller C. about 1000 times smaller D. about 100 million times smaller E. about 1 million times smaller Points Earned: 1/1 Correct Answer: Your Response: 8...