Download Practice Midterm 1

ASTR 001 Introduction to the Cosmos
Practice Midterm Exam #1
Name: HASSEN M. YESUF
• Select the answer (letter choices AE) that BEST fits the question.
• Write and bubble in your name and student ID on the Scantron sheet.
• Write your name on this exam script.
• Turn in BOTH your Scantron and this exam script to one of the proctors at the end of the exam.
• Dont worry about the Test Form bubble on the Scantron; we will fill that in for you.
Other notes:
• There are 30 questions in this practice exam. The actual exam is a bit longer. I recommend you plan to
spend 45 minutes on this practice exam. Answers are provided on the page 7.
• NO talking please!!!! If the exam proctors see a student talking or exchanging information with any of the
other students during the exam, they will make a note on the exam script of the student(s) in question, and
the student(s) will fail the exam.
• NO calculators, laptops, cell phones, iPods, or any other electronic devices please! The required math should
be doable on pencil/paper without the need for a calculator.
• This is an OPEN BOOK / OPEN NOTES exam, so textbooks and notes ARE allowed during the exam.
Good luck ! In unlikely case, if you are not satisfied with your score on the first midterm start going to sections
and office hours ,
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1. Which of the following is false?
A) The order of events can be different for observers in different reference frames.
B) From your point of view, time runs slower in the reference frame of anyone moving relative to you.
C) If one observer measures two events to be simultaneous, all observers must agree on their simultaneity.
D) Time dilation is an observationally verified fact.
E) Time runs slower near a black hole.
2. The Earth is farthest from the Sun in July and closest to the Sun in January. During which Northern
Hemisphere season is the Earth moving fastest in its orbit?
A) Summer
B) Fall
C) Winter
D) Spring
E) B and D
3. How are wavelength, frequency, and energy related for photons of light?
A) Longer wavelength means lower frequency and lower energy.
B) Longer wavelength means higher frequency and lower energy.
C) Longer wavelength means higher frequency and higher energy.
D) Longer wavelength means lower frequency and higher energy.
E) There is no simple relationship because different photons travel at different speeds.
4. Which of the following statements about lunar phases is true?
A) The time between new Moons is two weeks.
B) The time from one new Moon to the next new Moon is the same as the time from first-quarter Moon to thirdquarter Moon.
C) The full Moon sometimes rises around midnight.
D) It is possible to have two full Moons during January, but not during February.
E) It is possible to have two full Moons during November, but not during December.
5. What conditions are required for a solar eclipse?
A) The phase of the Moon must be new, and the nodes of the Moon’s orbit must be nearly aligned with Earth
and the Sun.
B) The phase of the Moon must be full, and the nodes of the Moon’s orbit must be nearly aligned with Earth and
the Sun.
C) The phase of the Moon can be new or full, and the nodes of the Moon’s orbit must be nearly aligned with Earth
and the Sun.
D) The phase of the Moon must be new, and the Moon’s orbital plane must lie in the ecliptic.
E) The phase of the Moon must be full, and the Moon’s orbital plane must lie in the ecliptic.
6. What would happen if the Space Shuttle were launched with a speed greater than Earth’s escape
velocity?
A) It would travel away from Earth into the solar system.
B) It would travel in a higher orbit around Earth.
C) It would take less time to reach its bound orbit.
D) It would orbit Earth at a faster velocity.
E) It would be in an unstable orbit.
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7. Which of the following is largest?
A) size of a typical galaxy
B) size of Pluto’s orbit
C) distance to the nearest star (other than our Sun)
D) 1 light-year
8. What does the equivalence principle of General Theory of Relativity say?
A) Gravity is the same thing as curvature of spacetime.
B) The effects of gravity are exactly equivalent to the effects of acceleration.
C) You cannot distinguish between motion at constant velocity and weight in a gravitational field.
D) The effects of relativity are exactly equivalent to those predicted by Newton’s laws of motion.
E) All observers must always measure the same (equivalent) weights for moving objects.
9. Which of the following best describes the Milky Way Galaxy?
A) a spiral galaxy with a disk about 100,000 light-years in diameter and containing between 100 billion and 1
trillion stars
B) a spiral galaxy with a disk about 1 billion kilometers in diameter and containing between 100 million and 1
billion stars
C) a spiral galaxy with a disk about 100,000 light-years in diameter and containing about 100,000 stars
D) a spherically shaped collection of stars including our solar system and about a dozen other solar systems,
stretching about 4 light-years in diameter
E) a spherically shaped collection of about 1 million stars that is about 100 light-years in diameter
10. Which of the following statements about the celestial equator is true at all latitudes?
A) It lies along the band of light we call the Milky Way.
B) It represents an extension of Earth’s equator onto the celestial sphere.
C) It cuts the dome of your sky exactly in half.
D) It extends from your horizon due east, through your zenith, to your horizon due west.
E) It extends from your horizon due north, through your zenith, to your horizon due south.
11. Which of the following correctly describes the meridian in your sky?
A) a half-circle extending from your horizon due east, through your zenith, to your horizon due west
B) a half-circle extending from your horizon due north, through your zenith, to your horizon due south
C) a half-circle extending from your horizon due east, through the north celestial pole, to your horizon due west
D) the point directly over your head
E) the boundary between the portion of the celestial sphere you can see at any moment and the portion that you
cannot see
12. When an atom absorbs a photon containing energy, any of the following can happen except which?
A) The atom becomes excited.
B) The atom is ionized.
C) An electron moves from an upper energy level to a lower one.
D) An electron moves from a lower energy level to an upper one.
13. At approximately what time would a first quarter Moon rise?
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A) 6 A.M.
B) 9 A.M.
C) noon
D) 6 P.M.
E) midnight
14. We can’t detect stellar parallax with naked-eye observations becausethe shifts in stellar positions are
too small. Which of the following would make parallax easier to observe?
A) increasing the size of Earth’s orbit
B) speeding up Earth’s rotational motion
C) slowing down Earth’s rotational motion
D) speeding up the precession of Earth’s axis
E) getting away from streetlights
15. How much electrical charge does an atom with 6 protons, 6 neutrons, and 5 electrons have?
A) a total charge of +17
B) a negative charge of -5
C) a positive charge of +7
D) a positive charge of +1
E) none of the above
16. When we see Venus in its full phase, what phase would Earth be in as seen by a hypothetical Venetian
on the daytime side?
A) full
B) new
C) first quarter
D) third quarter
E) waning crescent
17. Spectra from neutral atoms compared with spectra from ionized atoms of the same element
A) are the same.
B) are slightly redshifted.
C) are slightly blueshifted.
D) have different sets of spectral lines.
E) have the same sets of spectral lines but different widths for those lines.
18. An object moving by you at a half of the speed light will appear to have
about the effects on both mass and length).
A) a lower density than it has at rest.
B) a higher density than it has at rest.
C) a same density as it has at rest.
D) an infinite density
E) unknown density as density is beyond realm of special relativity
19. If we could measure the mass of the spaceship as it goes by, what would it be?
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(Hint: think
A) Its mass is infinite.
B) Its mass is greater than its rest mass.
C) Its mass is the same as it would be if it were not moving.
D) Its mass is less than its rest mass.
20. How would the passengers on the spaceship view our clocks?
A) Time is the same for everyone.
B) Our clocks are going fast.
C) Our clocks are going slow.
D) Our clocks are going at the same rate as theirs.
E) They can’t see our clocks, but we can see theirs.
21. Kepler’s second law, which states that as a planet moves around its orbit it sweeps out equal areas in
equal times, means that
A) a planet travels faster when it is nearer to the Sun and slower when it is farther from the Sun.
B) a planet’s period does not depend on the eccentricity of its orbit.
C) planets that are farther from the Sun move at slower average speeds than nearer planets.
D) the period of a planet does not depend on its mass.
E) planets have circular orbits.
22. According to general relativity, a black hole is
A) an object does not radiate therefore cannot be seen directy or otherwise.
B) a hole in space-time where the escape velocity is speed of light
C) a place where light travels slower than the normal speed of light.
D) a place where light travels faster than the normal speed of light.
E) a place where there is no gravity.
23. Each of the following is a prediction of the theory of relativity. Which one is crucial to understanding
how the Sun provides light and heat to Earth?
A) If you observe someone moving by you, you’ll see their time running slowly.
B) Gravity is curvature of spacetime.
C) E = mc2
D) Time runs slower on the surface of the Sun than on Earth.
E) Space is different for different observers. Time is different for different observers. Spacetime is the same for
everyone.
24. From Kepler’s third law, a hypothetical planet that is twice as far from the Sun as Earth should have
a period of
A) 1/2 Earth year.
B) 1 Earth year.
C) 2 Earth years.
D) more than 2 Earth years.
E) It depends on the planet’s mass.
25. Orion is visible on winter evenings but not summer evenings because of
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A) interference from the full Moon.
B) the tilt of Earth’s axis.
C) the location of Earth in its orbit.
D) the precession of Earth’s axis.
E) the retrograde motion during summer
26. Which planet has a solar day that is shorter than its sidereal day?
A) Venus
B) Jupiter
C) Mercury
D) Earth
E) Mars
27. A star that is located 30 degrees north of the celestial equator has:
A) right ascension = 30 degrees
B) latitude = 30 degrees
C) declination = 30 degrees
D) right ascension = 60 degrees
E) altitude = 30 degrees
28. When we say that a planet has a highly eccentric orbit, we mean that:
A) It is almost in a perfect circular orbit
B) its orbit is an ellipse with the Sun at the center.
C) in some parts of its orbit it is much closer to the Sun than in other parts.
D) it has high escape velocity
E) it is spiraling in toward the Sun.
29. What conditions are required for a lunar eclipse?
A) The phase of the Moon can be new or full, and the nodes of the Moon’s orbit must be nearly aligned with
Earth and the Sun.
B) The phase of the Moon must be new, and the nodes of the Moon’s orbit must be nearly aligned with Earth and
the Sun.
C) The phase of the Moon must be full, and the Moon’s orbital plane must lie in the ecliptic.
D) The phase of the Moon must be full, and the nodes of the Moon’s orbit must be nearly aligned with Earth and
the Sun.
E) The phase of the Moon must be new, and the Moon’s orbital plane must lie in the ecliptic.
30. What is a quasar?
A) a starlike object that actually represents a bright patch of gas in the Milky Way
B) a very large galaxy thought to be formed by the merger of several smaller galaxies, typically found in the center
of a galaxy cluster
C) a specialized astronomical instrument for observing distant stars
D) the extremely bright center of a distant galaxy, thought to be powered by a massive black hole
E) another name for very bright stars of spectral type Q
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Answers
1. C
2. C
3. A
4. D
5. A
6. A
7. A
8. B
9. A
10. B
11. B
12. C
13. C
14. A
15. D
16. A
17. D
18. B
19. B
20. C
21. A
22. B
23. C
24. D
25. C
26. A
27. C
28. C
29. D
30. D
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