Astronomy 1001 Midterm I Feb27-2003

 

The usual stuff here plus

 

Students are allowed one sheet (both sides) of notes.

 

 

Multiple Choice (30 questions at 3 points each for a total of 90)

 

1. Which of the following correctly describes the MERIDIAN in your sky?

a. a half-circle extending from your horizon due east, through your

zenith, to your horizon due west

b. a half-circle extending from your horizon due north, through your

zenith, to your horizon due south

c. a half-circle extending from your horizon due east, through the north

celestial pole, to your horizon due west

d. the point directly above your head

e. the boundary between the portion of the celestial sphere you can see at

any moment and the portion that you cannot see

 

2. Which of the following is NOT a characteristic of the inner planets?

a. They are relatively smaller than the outer planets.

b. They all have solid rocky surfaces.

c. They all have substantial atmospheres.

d. Their orbits are relatively closely spaced.

e. They have very few, if any, satellites.

 

3. Why is it summer in the northern hemisphere when it is winter in the

southern hemisphere?

a. The northern hemisphere is closer to the sun than the southern hemisphere.

b. The northern hemisphere is on top of the Earth and always receives more

sunlight than the southern hemisphere.

c. The northern hemisphere is tilted toward the sun and receives more

direct sunlight.

d. The northern hemisphere is tilted away from the sun and receives more

indirect sunlight.

e. It isn't; both hemispheres have the same seasons at the same time.

 

4. We cannot detect stellar parallax with naked-eye observations. Which of

the following would make stellar parallax easier to see?

a. increasing the size of the Earth's orbit

b. speeding up the Earth's orbital motion

c. slowing down the Earth's orbital motion

d. speeding up the precession of the Earth's axis

e. getting away from the "U"

 

5. Orion is visible on winter evenings but not summer evenings because

a. of interference from the full moon

b. the tilt of the Earth's axis of rotation

c. the location of the Earth in its orbit

d. the precession of Earth's axis of rotation

e. it's clearer in the winter than in the summer

 

6. If the moon is setting at noon, the phase of the moon must be

a. full

b. first quarter

c. waning crescent

d. third quarter

e. waxing crescent

 

7. In addition to the conditions required for any solar eclipse, what must

also be true in order for you to observe a total solar eclipse?

a. The Earth must lie completely within the moon's umbra.

b. The Earth must lie completely within the moon's penumbra.

c. The Earth must be near its aphelion in its orbit around the sun.

d. The moon's umbra must touch the area of the Earth where you are located.

e. The moon's penumbra must touch the area of the Earth where you are located.

8. Patterns of stars in the constellations hardly change in appearance

over several thousand years. Why?

a. Stars are fixed on the celestial sphere and never move.

b. Stars move, but they move very slowly--only a few kilometers in a

thousand years.

c. Although most stars move through the sky, the brightest stars do not,

and they are the ones that trace out the constellations in the sky.

d. The stars actually do move rapidly at speeds of thousands of

kilometers per hour but are so far away that it would take a tens of

thousands of years to make any noticeable change.

e. Stars within a constellation move together as a group which tends to

hide their actual motion and prevent the pattern from changing.

9. The conservation of angular momentum means that as a figure skater brings her arms in closer to her body she will

a. spin more slowly

b. spin faster

c. fall down

d. flatten because of the centrifugal force

e. spin with exactly the same speed

 

10. Why did Ptolemy have planets orbiting the Earth in circles upon

circles in the geocentric theory of the solar system?

a. to explain why more distant planets take longer to move through the zodiac than nearby ones

b. to explain why planets sometimes appear to move backwards in the sky

c. to explain why the Greeks were unable to detect stellar parallax

d. to properly account for the varying distances of the planets from the Earth

e. to explain why Venus goes through phases when observed from the Earth

 

11. What is temperature a measure of?

a. the average mass of particles in a substance

b. the average size of particles in a substance

c. the average kinetic energy or motion of particles in a substance

d. the total number of particles in a substance

e. the total potential energy of particles in a substance

 

12. What would happen if the Space Shuttle were launched with a speed

greater than the Earth's escape velocity?

a. It would travel away from the Earth into the rest of the solar system

b. It would travel in a higher orbit around the Earth

c. It would take less time to reach its bound orbit

d. It would orbit Earth with a faster velocity

e. It would be in a highly elliptical orbit

 

13. Newton's second law tells us that for the same force applied to two

objects of different mass

a. the more massive one will accelerate more than the less massive one

b. the less massive one will accelerate more than the more massive one

c. they will both accelerate by the same amount

d. they will not change their direction of motion

e. they will not change their speed of motion

 

14. Kepler's third law means that

a. a planet's period depends on the eccentricity of its orbit

b. orbits with the same semi-major axis can have different periods

c. the period of a planet depends on its mass

d. planets that are farther from the sun move at slower average speeds

than those closer to the sun

e. planets closer to the sun move at slower average speeds than those

farther from the sun

 

15. The force of gravity behaves as an inverse square law. This means

that if you double the distance between two large masses the gravitational

force between them

a. also doubles

b. strengthens by a factor of four

c. decreases by a factor of four

d. weakens by a factor of two

e. is unchanged

 

16. Kepler's second law means that

a. a planet travels faster in its orbit when it is nearer the sun and more

slowly when it is farther away

b. a planet's period does not depend on the eccentricity of the orbit

c. planets in orbits that are farther from the sun move at slower speeds

than those in orbits closer to the sun

d. the speed of a planet is the same at all points in its orbit

e. planets have circular orbits

 

17. The rings of Saturn are

a. probably due to the capture of millions of tiny asteroids from debris left over from the formation of the solar system.

b. solid disks of ice which formed with the planet

c. the remains of a satellite that was torn apart by tidal forces

d. a collection of comet nuclei captured by the planet

e. a complete mystery as yet unexplained as to their origin.

 

18. Which of the following is not an advantage of the Hubble Space

Telescope over ground-based telescopes?

a. It is closer to the stars

b. Stars do not twinkle when observed from space

c. It can observe infrared and ultraviolet radiation as well as visible light

d. It never has to close because of bad weather

e. Observers on the ground can use it at any time of the day or night

 

19. The relatively few craters that we see within the lunar maria

a. were formed by impacts that occurred before those that formed most of

the craters in the lunar highlands (very heavily cratered regions)

b. were formed by impacts that occurred after those that formed most of

the craters in the lunar highlands (very heavily cratered regions)

c. were created by the same large impactor that led to the formation of

the maria

d. are volcanic in origin

e. are sinkholes that formed when sections of the maria collapsed

 

20. Volcanism is

a. the excavation of bowl-shaped depressions by asteroids striking a

planet's surface

b. the eruption of molten rock from a planet's interior to its surface

c. the disruption of a planet by internal stresses

d. the wearing down of geological features by water and weather

e. the homeland of Vulcan

 

21. We have been able to map the surface features of Venus by

a. studying Venus from Earth with our most powerful telescopes

b. studying Venus with powerful telescopes on spacecraft sent to Venus

c. making computer models of geological processes on Venus

d. using radar from spacecraft sent to orbit Venus

e. landing spacecraft on Venus for detailed surface exploration


22. Why doesn't Venus have seasons as Earth and Mars do?

a. It does not have an ozone layer

b. It is too close to the sun

c. Its rotation axis is not tilted

d. It does not rotate fast enough

e. Its orbit is very elliptical

 

23. Tectonics describes

a. the production of craters by colliding comets and asteroids

b. the flow of molten rock through cracks in the planets surface

c. the disruption of a planet's surface by motions caused by internal stresses

d. earthquakes

e. destruction of mountains by glaciers

 

24. Earth's atmosphere contains only small amounts of carbon dioxide because

a. Earth's volcanoes didn't outgas as much carbon dioxide as those on Mars

and Venus

b. Most of the carbon dioxide was lost during the age of bombardment

c. Chemical reactions destroyed the carbon dioxide and produced nitrogen instead

d. Carbon dioxide dissolves in water and most of it is now contained in

the oceans and carbonate rocks

e. Earth doesn't have as strong a greenhouse effect as is present on Venus

 

25. Ridges in the middle of the ocean are places where

a. one plate slides under another, returning older crust to the mantle

b. hot mantle material rises upward creating volcanic islands

c. hot mantle material rises upward and spreads sideways pushing the

plates apart

d. plates push together creating ocean mountain ranges

e. plates slip sideways relative to one another

 

26. Which two properties are most important in determining the temperature

of a planet?

a. size and distance from the sun

b. size and chemical composition

c. size and atmosphere

d. internal temperature and atmosphere

e. distance from the sun and atmosphere

 

27. Dating the age of the Earth relies on

a. the radioactive decay of unstable isotopes

b. nuclear fusion in natural reactors

c. the counting of carbon 14 atoms

d. measuring the rate at which the rivers deposit salt in the oceans

e. finding fossils from different periods in the Earth's past

 

28. An isotope of an element like helium has

a. equal numbers of protons and neutrons

b. more protons than neutrons

c. extra neutrons compared to the normal helium atom

d. extra protons compared to the normal helium atom

e. extra electrons compared to the normal helium atom

 

29. From the shortest to the longest wavelength which of the following

correctly orders the different types of electromagnetic radiation?

a. infrared, visible light, ultraviolet, xrays, gamma rays, radio

b. radio, infrared, visible, ultraviolet, xrays, gamma rays

c. visible, infrared, xrays, ultraviolet, gamma rays, radio

d. gamma rays, xrays, ultraviolet, visible, infrared, radio

e. gamma rays, xrays, visible, ultraviolet, infrared, radio

 

30. What causes the apparent retrograde motion of the planets?

a. As the Earth passes another planet, its gravitational pull slows down

the other planet so that it appears to be traveling backwards

b. When planets are farther from the sun, they move more slowly than when

they are closer to the sun; it is during this slow period that they appear

to be moving backwards

c. The other planets never really move backwards; the background stars

shift because of the Earth's motion around the sun

d. As the Earth passes another planet, the other planet appears to move

backward with respect to the background stars, but the planet's motion

does not really change

e. Apparent retrograde motion is an illusion produced by turbulence in the

Earth's atmosphere

 

 

 

 

 

 

 

 

 

 

 

 

Essay questions (3 at 20 points each for a total of 60)

 

 

1.      Describe briefly three observations that Galileo made with the telescope and what effect they had on the geocentric theory for the solar system.   Include the most important observation that really was the death knell for the geocentric theory and explain why it was so important.

 

2.      A television commercial touts a 500-power telescope, with a two-inch objective lens, that can see objects millions of miles away with incredible clarity, all for just $19.95.  Consider the three functions of a telescope and assess the likely reality of the claims made for this particular telescope.  Note: there is no need to do any calculations to answer this question.  Just use your “scientific common sense” that you have been developing in this course.

 

3.      In magazines and movies astronauts are often shown moving inside a spacecraft where they seem to be just floating around and the statement is often made that they move like this because there is no gravity in outer space.  Is this correct?  Explain your answer in some detail explaining what is actually happening.