PH109 Exploring the Universe, Fall, 1999, Test #1

PH109 Exploring the Universe, Fall, 1999, Test #1

NAME______

Enter the best answer to the following questions on the answer sheet provided. Answer the essay questions on this copy of the test. Each question is worth 2 points unless noted otherwise.

1. The angular distance of an object from the horizon is its

a) latitude, b) declination, c) altitude, d) right ascension

2. The celestial equivalent of longitude is

a) declination, b) the horizon, c) precession, d) right ascension

3. The line which divides the celestial sphere into northern and southern hemispheres is the

a) ecliptic, b) celestial equator, c) meridian, d) horizon

4. What time is it when the Sun is on the meridian?

a) noon, b) midnight, c) sunset, d) sunrise

5. The ecliptic is the

a) projection of the Earth's equator on the celestial sphere

b) plane of the Earth's orbit projected onto the celestial sphere

c) apparent path of the moon on the celestial sphere

d) projection of the north celestial pole on the zodiac

6. On the first day of winter, the Sun is at the

a) solstice, b) equinox, c) nadir, d) zenith

7. The Sun moves eastward among the stars at the rate of about one degree per

a) hour, b) month, c) year, d) day

8 . What time of day does the third quarter Moon rise?

a) sunset, b) sunrise, c) noon, d) midnight

9. The Moon appears to have an angular size of 1/2 degree. If the Moon were twice as far away,what would be its new angular size if angular size  1/distance?

a) 1/2 degree, b) 1/3 degree, c) 1/4 degree, d) 1/5 degree

10. Why were epicycles used in Ptolemy's model of the solar system?

a) to account for the parallaxes of stars

b) to compensate for the ellipticity of the orbits of the planets

c) to explain the retrograde motions of planets

d) to explain the phenomenon of day and night

11. Which one of Kepler's laws explains what happens when a twilling ice skater brings their arms towards their center?

a) the planets follow ellipses, b) P2 = a3,

c) equal areas in equal times, d) Fg=GMM/d2

12. A hypothetical planet orbits the Sun a distance of 3 AU. What is its orbital period if you know P2=a3, where P is the period and a is the semi-major axis?

a) 2.8 years, b) 3.0 years, c) 5.2 years, d) 9.0 years

13. A shift in the direction of an object caused by a change in the position of an observer is called

a) parallax, b) precession, c) the Coriolis effect, d) epicycle motion

14. What happens to the angular momentum of a planet as it orbits the Sun?

a) it increases steadily with time, b) it gradually drops to zero

c) it increases and decreases as the planet changes speed, d) it remains constant

15. In the course of a year, how much of the universe could you see from the North pole

a) about one fourth, b) one half, c) about three fourths, d) all of it

16. If the Earth were inclined more on its axis than it currently is, what would be the consequences?

a) more drastic seasons, b) a longer year, c) more global warming, d) no solstices or equinoxes

17. Which constellation contains stars which "point" to the north star

a) Big Dipper, b) Orion, c) Little Dipper, d) Northern Cross

18. In the terrestrial coordinate system, which coordinate measures the distance from the equator

a) Latitude, b) Longitude, c) Zenith, d) Horizon

19.The projection of the Earth’s equator onto the celestial sphere defines the

a) circumpolar region, b) celestial equator, c) the Right Ascension, d)epicycle

20.Aliens abduct me but then set me down at a different place on the Earth (I think). I observe the diurnal motion of the stars and note that they rise straight up in the East go overhead and set straight in the West. Where am I?

a) North Pole, b) South Pole, c) Equator, d) Can’t Tell

21.I wake up in the middle of the night and notice that it is 12:00 midnight and that the Moon is on my meridian. What is the phase of the Moon that I see?

a) new Moon, b) first quarter, c) full Moon, d) third quarter

22.What is the relative size of the Moon to the Earth?

a) 1/4 as big, b) 1/2 as big, c) 1/3 as big, d) 1/10 as big

23.The changing in the direction of the Earth’s rotation axis is called

a) parallax, b) precession, c) it does not change it is fixed, d) the seasons

24.Given the equation FG = GMm/d2 , if two objects suddenly become separated by twice their distance, what happens to the gravitation force between them

a) stays the same, b) increases by a factor of four

c) decreases by a factor of four, d) increases by a factor of two

25.A planet in a highly elliptical orbit has its greatest speed when

a) it is farthest from the Sun, b) it is closest to the Sun

c) it is at the equinox, d) the speed is always the same

26. How long does a complete precession cycle take?

a) 60,000 years, b) 26,000 years, c) 6000 years, d) 4 years

27.The Moon is growing less full each night. This is called _____.

a) gibbous, b) waxing, c) waning, d) phases

28.A wave has a speed 10 m/s and frequency 2 Hz. What is its wavelength if C =, where C is the velocity, is the frequency, and  is the wavelength?

a) 80 m, b) 20 m, c) 5 m, d) 4 m

29.What does Wien's Law reveal?

a) White light consists of many different colors.

b) The farther away we look in space, the deeper we are looking into the past.

c) That the hotter the object, the bluer its radiation.

d) No known object can become hot enough to emit high-energy radiation.

30.A police officer tells me that I my red shift velocity exceeded posted limits. What does he mean?

a) you were speeding away from him, b) you were speeding toward him,

c) you were stopped, d) you were going too slow

31. When an electron resides at a greater-than-normal distance from its parent nucleus, the atom is said to be in what state?

a) Ground., b) Excited., c) Extended, d) Ionized

32.What is "seeing"?

a) It is a measure of the quality of a telescope's optical system.

b) It is a measure of the image quality due to the stability of the air.

c) It is a standard by which astronomers compare and contrast their own eyesight

d) It is a difference related strictly to cold- and warm-weather observing.

33. What is the approximate azimuth (az) elevation (el) of a star which is high in the West.

a) az= 180o, el= 90o b) az= 90o, el= 60o c) az= 270o, el=60o d) az=0o, el=10o

34. What region of the electromagnetic spectrum is our skin sensitive to

a) visible, b) infrared, c) x-ray, d) gamma-ray

35. When the Moon casts its shadow on the Earth, this is called a

a) lunar eclipse, b) solar eclipse, c) new Moon, d) Full Moon

36. Retrograde motion is when

a) planets stop their forward motion in their orbit and perform a loop in the sky

b) planets that orbit the Sun in a clockwise direction

c) the apparent loop a planet makes in the sky when overtaken by another planet

d) when planets are held back one grade instead of advancing

37. Newton invented this to help him solve Kepler's equations

a) algebra, b) calculus, c) trigonometry, d) protractor

38. What phase of the Moon does a lunar eclipse occur

a) new, b) first quarter, c) full, d) last quarter

39. Why is the Mix 104.7 radio tower as tall as it is

a) make sure signal can travel over the trees

b) get above the interference of the Earth

c) the wavelength is that long

d) to keep high energy waves away from the operators

40. Infrared astronomers get to put their telescopes in space because

a) political connections give them more money

b) they own part of the company that can launch spacecraft

c) it is cheaper to put it in space

d) infrared radiation can not penetrate the atmosphere

41. (10 points) Label the phases and times in the diagram below

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42. (10 points) Galileo observed the Moon, Sun, and planets Venus, and Jupiter with his new "telescope". What "new" discoveries did Galileo make concerning these objects and what were their significance.