ASTRONOMY 101
Mesa College
Fall 2002
First Examination
NAME______________________________(Print) Lec. hr.______ days class meets______
1 Due to the longer wavelengths being measured, radio telescopes are built with much larger reflecting diameters than optical telescopes.
a. true b. false
2 The Cassigrain focus for a reflecting telescope is located
a. in a separate room from the telescope c. at the side of the tube
b. behind the primary mirror d. inside the tube
3 The brightness of the image, when observed in a larger telescope, will appear
a. fainter b. to remain the same c. brighter
4 Galileo's first telescope was called a refractor because it utilized a ___________ to focus the light.
a. lens b. mirror
5 A photo multiplier is used to measure the ___________________ of a star.
a. speed
b. distance
c. chemical composition
d. mass
e. apparent brightness
6 The resolving power of a telescope
a. increases with diameter of the objective
b. decreases with diameter of the objective
c. is independent of objective diameter
7 Eratosthenes was the first person in the West to determine the circumference of the Earth.
a. true b. false
8 In the model of Aristotle, what is located at the exact center of the universe?
a. Sun c. Moon
b. Earth d. nothing
9 One of the most compelling bits of evidence that we live on a spherical earth is
a. the existence of a horizon.
b. the shape of the sun and the moon.
c. the rising and setting of the sun and the stars.
d. the shape of our shadow on the eclipsed moon.
10 From Kepler's law of areas describing planetary motion one may conclude that a planet in a non-circular orbit
a. moves more rapidly when it is nearest the sun (at perihelion)
than when it is farthest from the sun (at aphelion)
b. moves more rapidly when it is farthest from the sun than when it is closest
c. moves at the same rate throughout its orbit
d. moves always more rapidly when it is nearest earth (at
perigee) than when it is farthest from earth (apogee)
11 Which person do we associate with the Universal Law of Gravitation?
a. Galileo d. Copernicus
b. Kepler e. Newton
c. Ptolemy
12 In order to reproduce the retrograde(backward) motion of a planet Ptolemy made use of
a. an epicycle. b. an ellipse c. an equant d. the sun
13 Kepler found the orbit of Mars to be
a. a circle.
b. an ellipse with sun at one focus.
c. an ellipse with sun at center.
14 The Greeks of the first and second century BC were sure that the Earth was round because, among other reasons,
a. the stars were noted to rise about four minutes earlier each day than the day before
b. travelers reported a different appearance of the sky as seen from "southern" lands
c. Copernicus proved the Earth was a planet--hence it had to be round
d. the clockwise rotation of the Foucault pendulum
15 Kepler discovered his laws of planetary motion from a study of the observations of
a. Ptolemy c. Tycho Brahe e. Aristotle
b. Hipparchus d. Newton
16 Galileo made observations that clearly disproved the _______________system.
a. heliocentric (Copernican) b. Geocentric (Ptolemaic)
17 Copernicus was important to astronomy because he
a. proved that the Earth moves around the Sun.
b. rediscovered the notion that the Earth moves around the Sun
and that idea may have some advantages over the geocentric system.
c. was the first person to suggest that the Earth orbits the Sun.
d. was the first person able to predict planetary positions months in the future.
e. developed the telescope for use on the Moon.
18 Full moon rises at
a. noon b. sunset c. midnight d. sunrise
19 New moon rises at
a. noon b. sunset c. midnight d. sunrise
20 The Moon keeps the same face pointed toward the Earth.
a. true b. false
21 One of the daily high tides is caused by the Moon"pulling" harder on one side of the Earth than the other. The second daily high tide is caused by:
a. the Earth's rotation.
b. the Earth's revolution.
c. the Earth not being exactly spherical
d. the Earth being accelerated toward the Moon.
22 If the same force is applied to two objects which one will have the least acceleration?
a. the more massive one
b. the less massive one
c. both will have the same acceleration
23 Astronauts in a space vehicle experience weightlessness because
a. they have escaped from gravity
b. their rocket engine neutralizes gravity
c. they are falling at the same rate as is everything else in the vehicle
d. the moon counterbalances our gravity
e. none of the above is the correct reason
24 Consider a large white rabbit, dressed in a red vest and carrying a gold pocket watch, isolated away from Earth and all other celestial bodies. He is nibbling on a small carrot, but suddenly stops eating, glances at his watch, and throws the carrot away. What subsequently happens?
a. The carrot stops the instant it leaves the rabbit's paw.
b. The carrot "sails" a short distance and comes to rest.
c. The rabbit moves away from a motionless carrot.
d. The rabbit moves away, and so does the carrot, rabbit moving more slowly than the carrot.
e. The rabbit discovered he is late for the Hatter's tea.
25 If you double the separation between two objects, then
a. The strength of the gravitational force between them will become 4 times stronger.
b. The strength of the gravitational force between them will remain the same.
c. The strength of the gravitational force between them will become 2 times weaker.
d. The strength of the gravitational force between them will become 4 times weaker.
26 Which has the greatest energy?
a. radio waves c. x-rays
b. visible light d. ultraviolet
27 Which has the greatest wavelength?
a. radio waves c. x-rays
b. visible light d. ultraviolet
28 An absorption 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
29 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
30 In an electron moves from a smaller to a larger 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
31 X-rays travel faster through space that radio waves.
a. true b. false
32 How much more or less energy would get to your eye from a star if it were moved to twice its present distance?
a. half as much c. 2 times more
b. 4 times more d. 4 times less
33 The physical law called Wien's Law (don't get excited, you don't have to do any calculations with it!) says the following.
a. As an object becomes hotter, it increasingly concentrates its radiation in a narrower range of wavelengths.
b. The force between two masses is inversely proportional to the distance between them.
c. As an object becomes hotter, it shifts its emitted radiation to shorter wavelengths.
d. Hot objects are less efficient in the generation of electromagnetic radiation than cool objects.
e. The shorter the wavelength of electromagnetic radiation, the greater the mass of the particle, or photon that is carrying the radiation.
34 The seasons are primarily due to
a. sunspots
b. the precession of the earth's axis
c. the tilt of the Earth's axis of rotation with respect to the orbital plane
d. the precession of the earth's orbit
e. the ellipticity of the earth's orbit
35 The Foucault Pendulum experiment proved the
a. Earth orbits the Sun
b. Earth rotates on its axis
c. stars are much farther away than the ancient Greeks thought
d. Earth has an elliptical orbit
36 Which of the following is not something to look for in a good site for an observatory?
a. Low elevation. c. Dark sky.
b. Atmospheric stability. d. Low humidity.
37 An important piece of auxiliary equipment at an astronomical observatory used to break light from a celestial source into its component colors is called a
a. spectrograph d. stethoscope
b. barograph e. stereoscope
c. micrometer
38 Charged coupled devices (CCDs) are almost 100 times more sensitive to faint signals than photographic film.
a. true b. false
39 The planet Neptune was discovered
a. by accident during a search for comets
b. as a result of the analysis of the perturbations observed in the orbit of Uranus
c. by Greek astronomers in the year 1800 A.D.
40 A Doppler shift in the spectral lines of a star tells us
a. how fast light travels
b. the star's distance
c. how fast the star is moving relative to us
41 A crescent moon appears as
a. over half illuminated c. less than half illuminated
b. 100% illuminated d. exactly 1/2 illuminated
42 Right Ascension & Declination is a coordinate system used to locate
a. cities on the Earth b. stars in the sky
43 A solar day is one rotation of the Earth relative to the
a. Sun b. stars
44 Since the axis of rotation of the Earth "wobbles"
a. the Earth will some day fly out of the Solar System
b. the Earth will some day turn upside down
c. we will always have earthquakes
d. the position of the celestial pole will change relative to the stars
45 Which of the following are listed in the proper order, starting with nearest and ending with the most distant?
a. earth, quasar, galaxy, sun
b. sun, galaxy, sun, quasar
c. earth, sun, quasar, galaxy
d. earth, sun, galaxy, quasar
46 During a total eclipse of the moon, the moon must lie
a. completely within the moon's shadow.
b. completely within the sun's shadow.
c. completely within Earth's shadow.
d. partially within the moon's shadow.
47 The law of reflection 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.
48 An example of refraction is
a. light reflecting off a mirror
b. the Earth's rotational axis "wobbling"
c. the elliptical orbit of the Earth
d. the bending of light as it goes through glass
49 Which particles are located in the nucleus of an atom?
a. electrons & protons c. neutron & protons
b. electrons & neutrons d. electrons, protons, & neutrons
50 Which has the most momentum?
a. a 1 ton car going 60 mi/hr
b. a 10 ton truck going 60 mi/hr
c. both have the same momentum because the are both going at the same speed
In a drawing, show how the Sun, Moon, and Earth would have to be aligned so that the Moon would appear in its new phase from the Earth. 2 points
Why did the earth have to placed off center in the model of Ptolemy? 3 points
Give the argument based on observations of ships coming into port that shows that the Earth is spherical. 2 points
How would an ancient observer discover a new planet? 2 points
Make a sketch of the Copernican model of the solar system, being sure to indicate the locations of the Earth, moon and Sun. Be sure to indicate the assumed shape of the orbits.
4 points
From the discussion in class, why were Galileo's observations of Venus so important? 2 points
Give the definition of the Zenith. 2 points
Describe the two models of light as discussed in class. 2 points each
1
2
Why have so few people seen a total eclipse of the Sun compared to one of the Moon?
2 points
Give two of the major advantages of locating an observatory on the top of a mountain.
Describe the three parts of the (scientific) Method. Give the three major parts in the proper order. 3 points
1
2
3
State the major difference between a scientific truth & absolute truth. 2 points
Describe the technique that Eratosthenes used to measure the circumference of the Earth.
2 points
What is the difference between the sidereal day and the solar day? 2 points
List the following in order of increasing distance from the Earth: Sun, next galaxy, Moon, quasar. 1 point each
1._____________________
2._____________________
3._____________________
4._____________________
Describe (astronomical) seeing. 2 points
Give the definition of the sidereal day. 2 points
Describe the method used to determine the distance to the nearer planets using radar astronomy.
2 points
Describe the basic operation of a radio telescope. 3 points
Describe the appearance of the full & new moons. 2 points
full
new
Why are observatories located on the tops of mountains. Two important reasons.
1 point each
Give two of the major advantages of a reflecting telescope over a refracting one. 2 points
1
2
Describe three instruments that are attached to telescopes to collect and sometimes analysis light. 1 point each
1
2
3