Astronomy 100

Section 2, Fall 2008

Hour Exam 1 Form A

Answers

1. The astronomical unit is the average distance between the
d) Earth and Sun

2. Neptune is about how many AU from the Sun.
d) 30

3. The Earth's diameter is roughly
b) 8000 miles

4. What planet is between Saturn and Neptune?
b) Uranus

5. A city is 1/3 of the way from the equator to the south pole. Its latitude is
b) 30 degrees south

6. Your latitude is 25 degrees north. What is the altitude of the north celestial pole?
b) 25 degrees

7. "South" is defined by the intersections of the
e) celestial meridian and horizon

8. A star is a two-thirds of the way from the celestial equator to the north celestial pole. Where will it rise for an observer at the equator?
c) northeast

9. At a latitude of 60 degrees north, the celestial equator runs
d) from exact east to exact west

10. Where on Earth would you see the fewest circumpolar stars?
d) equator

11. What is the best evidence for a rotating Earth (and not a rotating sky)?
a) Foucault pendulum

12. The obliquity of the ecliptic is
e) 23.5 degrees

13. When will the Sun appear lowest in the sky at noon as seen from Chicago?
b) December 22

14. It is cooler in winter than in summer because of
b) the obliquity of the ecliptic

15. The Sun passes overhead on June 21 at
c) the tropic of Cancer

16. The Sun is seen for 6 months straight
a) at the south pole

17. The Earth is at its perihelion point about
a) January 2

18. Polaris, the North Star, is in
a) Ursa Minor

19. Which is a constellation of the Zodiac?
b) Aquarius

20. The modern constellations were invented
d) between 1600 and 1800 AD

21. The brightest star in a constellation is usually called
d) lower case Greek alpha

22. Most star names are
b) Arabic

23. When the Moon is in its first quarter we are seeing
e) half the nighttime side of the Moon, half the daytime side

24. What is the lunar phase when the Moon is 90 degrees to the east of the Sun (that is, it has gone 90 degrees around its orbit from new Moon)?
c) first quarter

25. Eclipses of the Moon can take place only at
e) full Moon

26. When the Moon is in total eclipse it is still seen because
d) of light that is scattered into the shadow by the Earth's atmosphere

27. A total eclipse of the Sun (when none of the bright portion of the Sun can be seen) takes place with the Moon near
a) perigee (closest to Earth)

28. When Jupiter is in retrograde motion, it is close to
a) opposition to the Sun

29. Which planet can be seen in a crescent phase from Earth?
a) Venus

30. What is at (or near) the focus of Venus's orbit?
b) Sun


31. Who discovered Uranus?
b) Herschel

32. An inferior planet moves fastest in orbit in kilometers per second when it is at
c) perihelion

33. What observation below best supports (or pertains to) Copernican heliocentric theory?
a) retrograde motion

34. For a planet of the Solar System, the sidereal period in years squared equals the semimajor axis in AU raised to what power?
b) 3

35. If you were to halve the mass of the Earth, but keep the radius the same you would weigh
c) 1/2 as much as you do now

36. What curve(s) lead(s) to orbits that are open ended (such that an orbiting body will not return)?
d) both a parabola and a hyperbola

37. Orbiting astronauts are weightless because
e) they and their craft falling with the same acceleration

38. A planet does not move in a straight line, but is in an elliptical orbit about the Sun, because of the acceleration provided by
a) gravity

39. The movement of what planet was responsible for the discovery of Neptune?
e) Uranus

40. The mass of the Sun is derived from
e) Kepler's third law as generalized by Newton


41. Planetary orbits are not perfect ellipses because of
e) the gravitational pulls of the planets on each other and on the Sun

42. In Einstein's theory of relativity, gravity is caused by
d) a distortion (bending) of spacetime caused by mass

43. Which particle carries the positive electric charge?
a) the proton

44. Which force holds the electrons to the atomic nucleus
d) electromagnetic

45. The kind of chemical element (whether hydrogen, carbon, iron, etc.) is determined by the number of nuclear
a) protons

46. The isotopes of any particular chemical element depend on the number of nuclear
c) neutrons

47. Which force holds the neutrons to the protons in an atomic nucleus
a) strong

48. The speed of light is
b) 186,000 miles per second

49. The electromagnetic radiation below with the longest wavelength is
c) infrared

50. What kind of radiation is responsible for sunburns?
d) ultraviolet light