Homework Set #1
1. In scientific notation, we would express the number 0.0035 as
A. 3.5 X 103.
B. 3 orders of magnitude.
C. 3.5 X 10-4.
D. 35 X 10-3.
E. None of the Above
2. Divide 4x1021 by 2x107.
A. 2 x 103
B. 2 x 1014
C. 2 x 1028
D. 8 x 1028
E. 8 x 1014
3. The Astronomical Unit (AU) is defined as
A. the distance between the Earth and the nearest star.
B. the distance between the Earth and the Moon.
C. the time it takes light to travel from the Sun to Earth.
D. the typical distance between stars in the galaxy.
E. the distance between the Sun and the Earth.
4. What does the observed angular size of an object depends upon?
A. apparent size divided distance.
B. true size divided by distance.
C. diameter times apparent size.
D. apparent size times true size.
E. true size times distance.
5. Suppose you measure the angular size of an object that you think is 10 feet in width and located 100 feet away from you. You later discover that the object is actually 20 feet in width and that it was located 200 feet away from you. How should you modify your conclusion about its angular size, based on this information?
A. You should double it.
B. You should cut it in half.
C. All you can do is remeasure.
D. There is not enough information to answer this question.
E. Both situations result in the SAME angular size.
6. What do we mean by the ALTITUDE of a celestial object?
A. its distance above the ground, in miles or kilometers.
B. its angular distance from the north point in the sky.
C. its angular distance above the horizon.
D. its angular distance from the east or west point on the horizon.
E. its angular distance from the Sun.
7. At the Earth's equator, you could see
A. all the stars in the sky at some time of the year or another.
B. no more than 50% of the sky at some time of the year or another.
C. the same thing that an observer anywhere else on Earth sees.
D. stars moving parallel to the horizon.
8. You are kidnapped, drugged, and flown somewhere. After an indefinite time in a dark cell, you escape and try to determine from the sky where you are and what time of year it is. What could you say about your location on Earth and the time of year if: you find Polaris and estimate its ALTITUDE to be 85 degrees above the north horizon.
A. You are at 85 degrees north latitude, between September 21st and March 21st
B. You are at 85 degrees south latitude, at any time of year
C. You are at 85 degrees north latitude, at equinox time
D. You are located on the ecliptic
E. There is not enough information to answer.
9. The celestial equator refers to
A. the projection of your horizon onto the sky.
B. the great circle on the sky that would result from extending the plane of the Earth's equator out to the celestial sphere.
C. the apparent path of the Sun among the stars during the Solar year.
D. the appearance of the celestial sphere as seen by an observer located somewhere on the Earth's equator.
E. the great circle on the celestial sphere that traces the path of the Milky Way across the sky.
10. Consider an observer at the equator. The Sun will be at its highest point above the horizon at noon
A. on the day of the summer solstice.
B. on the day of either equinox.
C. on the day of the winter solstice.
D. any day of the year because the altitude does not change with season anywhere on Earth.
E. any day of the year because the altitude does not change with season at the equator.
11. When does the Sun reach its maximum altitude in the sky for an observer south of latitude 23.5 degrees south?
A. on the vernal equinox.
B. on the June solstice.
C. on the autumnal equinox.
D. on the December solstice.
12. When the Earth, Moon, and Sun are occupying the positions shown
in the Figure A, what phase of the -Earth- would we see if we were
looking -from- the Moon?
13. Suppose the Earth, Moon, and Sun are in the relative positions
shown in the Figure A, for which we are looking down on the solar
system from the north. What lunar phase would be seen next?
B. first quarter
C. third quarter
14. If a star rises at midnight, then two weeks -later- it will rise at approximately
B. 11:30 P.M.
C. 11:00 P.M.
D. 12:30 A.M.
E. 1:00 A.M.
15. Where on the Earth are no stars circumpolar?
A. at the north pole
B. at the south pole
C. at the equator
E. Both A and B
16. The word "ecliptic" refers to
A. the apparent path of the Sun among the stars during the year.
B. the name of the plane close to which lie the orbits of the planets.
C. both A and B.
D. the non-circularity of the orbits of the planets.
E. the extension of the Earth's equator out to the plane of the sky.
17. You are kidnapped, drugged and flown somewhere. After an indefinite time in a dark cell you escape and start sky observations to tell where you are and what time of the year it is. Which of the following statement would be true for certain about your location and time of year if you observe that night and day are each exactly 12 hours long.
A. You could be anywhere on Earth (except the poles) if it is at an equinox.
B. You could be on the equator of the Earth at any time of year.
C. You are at one of the poles.
D. You are in the Northern Hemisphere at the summer solstice.
E. You are in the Southern Hemisphere on June 21st.
18. At the south pole, how long is it between the time when a star is observed to rise in the east and set in the west?
A. one Solar day
B. one sidereal day
C. half a sidereal day
D. Half a Solar day
E. Stars don't rise and set at the south pole.
19. If the Sun sets at 6:00, at about what time does the first quarter Moon rise?
A. 9 A.M.
C. 6 P.M.
D. 9 P.M.
20. Which of the following would you expect to observe from a round Earth?
A. The Sun's height above the horizon should always be nearly the same.
B. The shadow on the Moon during an eclipse should be a straight line.
C. The stars should rise and set every 24 hours.
D. The constellations visible should change as the observer changes longitude.
E. The constellations visible should change as the observer changes latitude
21. Summers are warmer than winters primarily because
A. the Earth is closer to the Sun in summer.
B. the days are longer in the summer.
C. the Sun is at a higher altitude in the sky.
D. the Sun emits more energy in the summer.
E. the Moon contributes more to Earth's heat in the summer than it does in the winter.
22. If the Earth had its rotation axis perpendicular to its orbital plane
A. its seasons would be the same as they are now because the Earth's rotation is perpendicular to its orbital plane.
B. it would not have seasons.
C. its seasonal changes would be more intense than they are now.
D. its seasons would be the same as they are now because the angle of the axis tilt has nothing to do with seasons.
23. When do lunar eclipses occur?
A. at full Moon.
B. at new Moon.
C. at quarter Moon.
D. at random phases of the Moon.
E. at any time because lunar phase is not involved.
24. What phase will Venus, which is closer to the Sun than is the Earth, have when it is at its closest to the Earth?
E. none; Venus does not show phases.
25. If a star rises at midnight, then one month from now it will rise at
A. 10:00 P.M.
B. 11:00 P.M.
C. 11:30 P.M.
D. 2:00 A.M.
E. 4:00 A.M.
26. If the altitude of the polestar is 20 degrees, at what angle (in degrees) do the stars rise and set with respect to the horizon?
B. 90 - 20 = 70
C. 20 + 45 = 65
27. For an observer at the equator, where on the celestial sphere will the north celestial pole be located?
A. on the eastern horizon
B. on the northern horizon
C. on the western horizon
D. on the southern horizon
E. directly overhead
28. What are constellations?
A. Groups of galaxies seen clustered in the night sky.
B. Groups of stars that make an apparent pattern in the sky.
C. Groups of stars that are gravitationally bound to each other.
D. Relics of the past, unrelated to modern-day astronomy.
29. Polaris, the North Star, does not appear to move in the sky because:
A. The stars are fixed relative to each other.
B. It lies approximately over the northern axis of the Earth.
C. It is too nearby for its motion to be discernible.
D. It is located directly overhead for everyone on Earth.