ASTRONOMY 101

Mesa College

Spring 2004

First Examination



NAME______________________________(Print) Lec. hr.______ days class meets______



NAME______________________________(Signature) select best answer





1 If two objects are acted on by the same force, the more massive one will

a. accelerate less d. have a faster speed

b. accelerate more e. be affected more by friction

c. have a slower speed



2 In the following list, the observation that was not first made by Galileo was of

a. craters on the moon.

b. the four largest moons of Jupiter.

c. the phases of Venus.

d. the lunar eclipse.



3 The four large moons around Jupiter were discovered by

a. Ptolemy d. Galileo

b. Tycho Brahe e. Copernicus

c. Kepler



4 Which model do you ascribe to Ptolemy?

a. heliocentric

b. flat earth

c. geocentric

d. couldn't receive light sent out by the sun



5 If a glowing object is moved 12 times farther away, how many times less light will get to the eye?

a. 12 times less c. 2.5 times less

b. 24 times less d. 144 times less



6 What is the primary advantage of the Hubble Space Telescope over ground-based telescopes?

a. It is above the atmosphere.

b. Its instruments are more sophisticated than any on Earth.

c. It is the largest telescope ever built.

d. Its mirror is the most perfect ever built.



7 An emission spectra appears as

a. a black background interspersed with narrow lines of color

b. an unbroken band of color, from deep red to a dark purple

c. a rainbow of color interspersed with narrow black lines



8 Which if the following statements about photons is FALSE?

a. photons always travel at the speed of light in a vacuum.

b. photons each carry a specific amount of energy

c. a photon of light cannot pass through the atmosphere of the earth, and thus cannot be seen at the Earth's surface.



9 Tycho's principle contribution to astronomy was

a. his being of noble blood

b. his suggested model of the solar system

c. the instruments and observations he made



10 The elliptical nature of planetary orbits was discovered by

a. Ptolemy c. Galileo e. Tennyson

b. Copernicus d. Kepler



11 The person we associate with the model of the solar system having the Sun in the center is

a. Ptolemy b. Copernicus c. Aristotle



12 The ancient Greek who determined the diameter of the Earth was

a. Tycho d. Kepler

b. Nick the Greek e. Aristotle

c. Eratosthenes



13 The sidereal day is one rotation of the earth relative to the

a. sun b. stars c. center of Galaxy



14 The point in the sky directly above your head at any given time is called the

a. nadir b. zenith c. celestial pole d. horizon point



15 The average distance between the Earth & the sun is called:

a. a light year c. light second

b. an orbital period d. astronomical unit (AU)



16 The closest star to the Sun is roughly how many light years away?

a. 4 b. 1000 c. 9 trillion d. less than 1



17 A continuous spectra appears as

a. a black background interspersed with narrow lines of color

b. an unbroken band of color, from deep red to a dark purple

c. a rainbow of color interspersed with narrow black lines



18 If the earth's equator were in the same plane as its orbit (instead of inclined 23 1/2 degrees) but all else was unchanged (rotation period: 24 hrs; orbit period 1 yr, etc.) then

a. seasonal variations would virtually disappear

b. winters would be colder and summer hotter than now

c. San Diego's climate would be similar to that of the tropics

d. San Diego would probably have a climate much like that of Nome,

Alaska



19 The Foucault pendulum demonstrates what motion of the earth?

a. rotation b. precession c. revolution d. none of these



20 If you could get twice as far away from the center of the earth as you are now, you would weigh

a. 1/2 less b. twice as much c. 1/4 as much d. four times as much



21 Which object has the greatest linear momentum?

a. 10 kg object moving at 10 meters/sec

b. 10 kg object moving at 20 meters/sec

c. 10 kg object moving at 30 meters/sec

d. 10 kg object that is not moving



22 A total eclipse of the moon may occur only when the moon is

a. new d. full

b. first quarter e. none of these

c. third quarter



23 The period of revolution of the Moon about the Earth & the Moon's period of rotation are

a. basically the same

b. different, the rotation period is much longer then the period of revolution.

c. different, the period of revolution is much longer then the rotation period



24 To the eye, the new moon appears

a. as fully illuminated.

b. 1/2 illuminated.

c. as unilluminated, and therefor can't be seen.





25 New moon rises(about) at

a. noon b. sunset c. midnight d. sunrise



26 The moon is full

a. when it and the sun are in opposite directions in the sky (at opposition)

b. when it and the sun are in the same direction in the sky (at conjunction)

c. a week after it is new



27 In an electron moves from a larger to a smaller orbit in an atom, this change can help produce

a. a Doppler shift

b. a dark (absorption) spectral line

c. a gravitational red shift

d. a bright (emission) spectral line

e. an ionized atom



28 The law of refraction(like light passing through a prism) says that

a. the angle of the incoming ray of light is equal to the angle of the outgoing light ray.

b. light is bent toward the normal(perpendicular) when to goes from a lower density material to a higher density material.

c. the speed of light is a constant.

d. red light has a longer wavelength than blue light.



29 Which has the greatest energy?

a. radio waves b. x-rays c. visible light d. ultraviolet



30 Which has the greatest wavelength?

a. radio waves b. x-rays c. visible light d. ultraviolet

31 The absorption lines in the spectrum of a star which is receding from us will appear

a. undisplaced d. displaced to longer wavelength

b. displaced to shorter wavelength e. strengthened

c. weakened



32 The Doppler effect is used to measure stellar

a. mass d. velocity

b. luminosity e. distance

c. temperature



33 Charged Coupled Devices (CCDs) are almost 100 times more sensitive than photographic film.

a. true b. false



34 When light is reflected off a reflecting surface its angle of incidence is always

a. greater than the angle of reflection

b. smaller than the angle of reflection

c. the same as the angle of reflection



35 One way to measure the temperature of a star would be to

a. measure the maximum wavelength which it emits

b. measure the wavelength of the brightest portion of its spectrum

c. measure the wavelengths of its hydrogen (Balmer) lines

d. none of the above methods can be used



36 In a refracting telescope, light is first collected by a lens.

a. true b. false



37 In a reflecting telescope, light is first collected by a lens.

a. true b. false



38 Optical astronomers work at night; optical solar astronomers work in the daytime; what is the work schedule of radio astronomers?

a. daytime only b. nighttime only c. night or daytime



39 Radio astronomy really came into being

a. over 100 years ago

b. after World War II, but more than 30 years ago

c. just 10 years ago



40 To break up light into the component colors, astronomers use a device called:

a. a telescope c. a CCD

b. spectrograph d. Cassegrain splitter



41 The earliest telescopes used by astronomers were:

a. reflectors b. refractors c. radio telescopes



42 In regards to a telescope, the focus is the

a. distance between the primary lens or mirror and the focus.

b. primary light gathering part of a telescope.

c. location of the image, or where the light is concentrated.



43 In regards to a telescope, the focal length is the

a. distance between the primary lens or mirror and the focus.

b. primary light gathering part of a telescope.

c. location of the image, or where the light is concentrated.





44 Fewer people have seen a total solar eclipse than have seen a total lunar eclipse because

a. solar eclipses are more frequent than solar eclipses

b. solar eclipses are more spectacular

c. most solar eclipses occur during the winter when the sky is cloudy

d. solar eclipses are visible over smaller parts of the earth

e. a total solar eclipse is difficult to observe because of its brightness



45 What is the phase of the moon just before the start of a total eclipse of the moon?

a. full b. crescent c. 1st quarter d. new



46 The celestial poles are the projection of the ____________ into the sky.

a. Earth's poles d. Moon's orbital plane

b. Moon's poles e. Earth's equator

c. Moon's equator



47 A coordinate system used by astronomers to locate objects in the sky is right ascension and declination.

a. true b. false





Explain the(2) causes of the 2 high tides that are experienced each day. 4 points



1



2









Describe the two models of light discussed in class. 4 points



1





2



From the class discussion, why were Galileo's observations the moons of Jupiter so important?

2 points





Is your name on the scantron and examination? ______(yes or no) 1 point