Sample Exam #3 Questions
1)The mass of the Sun is closest to which of the values below?
A)300 Earth masses
B)3,000 Earth masses
C)30,000 Earth masses
D)300,000 Earth masses
E)3,000,000 Earth masses
2)The Sun is approximately how much larger in radius than the Earth?
A)100 Earth radii
B)1,000 Earth radii
C)10,000 Earth radii
D)100,000 Earth radii
E)1,000,000 Earth radii
3)The density of the Sun is closest to the density of ….
A)Iron, 8 g/cm3
B)Rock, 5 g/cm3
C)Water, 1 g/cm3
D)Ice, 0.9 g/cm3
E)Air, 0.001 g/cm3
4)The surface temperature of the Sun is….
A)32,000 K
B)15,500 K
C)7,200 K
D)5,800 K
E)1,600 K
5)The core of the Sun has a temperature of…
A)Unknown
B)15 Million K
C)50 Million K
D)100 Million K
E)1.4 Billion K
6)The Sun can be functionally divided into two layers. Describe the physical characteristics of the two layers in the boxes below.
7)In a sentence or two, describe the functional difference between the core and envelope. In other words, what purpose does the core serve in the star’s function and what purpose does the envelope serve in the star’s function?
8)On this page, write an essay that describes how the Sun produces energy by explaining the net proton-proton chain reaction, define the symbols in the net reaction, stating the origin of the terms in the net reaction, and describing the significance of thermalization of solar gamma rays.
Please answer the following multiple choice/fill in the blank questions directly on the exam sheet.
9)There is a number line below which is marked in AU. On that number line mark the positions of the eight planets from the Sun, which is at 0 AU, as precisely as you can. You may use the first letter of the planet’s name as an identifier.
10)Which of the planets listed below has a mass of just about 1/2 the mass of the Earth?
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A)Mercury
B)Mars
C)Earth
D)Uranus
E)Venus
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11)Which of the values listed below best represents the mass of Saturn?
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A)1,000 Earth masses
B)300 Earth masses
C)100 Earth masses
D)30 Earth masses
E)10 Earth masses
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12)For which of the reasons below is Venus sometimes called Earth’s “sister” planet?
A)Venus has one moon orbiting it just as the Earth does.
B)The atmosphere of Venus contains N2 and O2 just like the Earth.
C)The Venus spins at the just about the same rate as the Earth so that their day lengths are about equal.
D)The mass and radius of Venus is just about the same as those of the Earth.
E)Venus has a strong magnetic field like the Earth
13)Which of the following is NOT a characteristic of the Terrestrial planets?
A)They have very few, if any, natural satellites.
B)Their solid surfaces.
C)Their atmospheres are primarily made of carbon dioxide and/or nitrogen.
D)Their orbits are separated by relatively large distances.
E)They rotate relatively slowly on their axes.
14)What is the most abundant gas in an interstellar cloud? ______
15)What is the second most abundant molecule that would form from random collisions in cosmic mix of elements?
______
16)The image below is meant to represent the solar nebula. In the box on the figure insert the appropriate values for the diameter of the solar nebula
17)State or identify the source of energy that provided initial heating of the solar nebula even before the Sun was formed.
A)Radioactive decay of heavy elements like uranium
B)Gravitational collapse of the nebular gas was converted into heat
C)Nuclear fusion of light elements like hydrogen
D)Friction of dust grains rubbing against each other within the cloud
E)Nearby stars heated the nebula with their star-light
18)The image to the right is of the nucleus of Comet Hartley 2. The nucleus is only about 2 km long. Comets like this are examples of which of the following objects?
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A)UFO
B)Dwarf Planet
C)Interstellar dust grain
D)Solar Nebula
E)Planetesimal
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19)When planets first, slowly and gently, started to form within the solar nebula, which process below caused that growth?
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A)Accretion
B)Coalescence
C)Collisions
D)Condensation
E)All the above
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20)Scientists are still unsure as to the origin of the Earth’s oceans. Circle the hypotheses below that are currently be investigated regarding the origin of the Earth’s oceans. (Circle all that apply)
A)Comets delivered water to fill the oceans to the Earth after it had formed.
B)The water came from water rich icy planetesimals that the Earth formed from.
C)The water is outgassed from volcanoes that release the small amount of water bound in the original rocks the Earth formed from.
D)The water was captured as it evaporated off the Sun’s surface.
21)Which of the processes below terminated the formation of the planets in our solar system?
A)All the gas, dust and ice were consumed by the planets leaving no more material left to grow with.
B)A nearby supernova removed all the unbound gas, dust and ice from our system thus starving the planet formation process.
C)All the rock fell into the Sun and the ice melted and evaporated into space, again, starving the planet growth process.
D)The initial burst of energy from the newly ”turned on” Sun swept the solar system clear of the raw materials needed to grow planets.
E)The seventh day ended.
Planet Name / Mass in Jupiter Masses / Semi-major Axis of Orbit in AU / EccentricityHD 231701b / 1.08 / 0.53 / 0.1
HD 93083b / 0.37 / 0.477 / 0.14
HD 32518b / 3.04 / 0.59 / 0.01
HD 154672b / 5.02 / 0.6 / 0.61
HD 145457b / 2.9 / 0.76 / 0.112
To the right are listed 5 of the known planets around other stars. The table contains the planet name, mass, semi-major axis of its orbit and its eccentricity.
22)What is the average mass of these planets in Jupiter masses and Earth masses?
Average mass = ______= ______
23)Which of the five planets listed above has the most non-circular orbit?
Planet Name ______
24)Which of the planets above seems to be most similar to our planetary system?
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A)HD 231701b
B)HD 93083b
C)HD 32518b
D)HD 154672b
E)HD 145457b
F)None of them
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25)Calculate the average semi-major axis of five exoplanets planet’s orbits in listed in the table for question #22 and in a few sentences characterize these planetary systems given their average mass (from question #22) and average semi-major axis, explicitly stating how they appear to be different from the planetary systems the Solar Nebula Model would predict.
26)Examine the characteristics of the planet HD 231701blisted in the table for question #22. Propose a mechanism, in a few sentences, that would place this planet into the orbit it currently has assuming that it originally formed about 5 AU from its star.
27)Examine the characteristics of the planetHD 145457b. It is 0.76 AU from its parent star. The distance to the star is 411 ly. What is the angular separation between the planet and its parent star in degrees and arcseconds?
28)The radial velocity curve of a star known as Upsilon Andromeda. Assuming that the star is similar to our Sun, what can you say (quantitatively) regarding the planet(s) that surround this star?
29)In a few sentences quantitatively describe the typical Jovian planet.
30)In a few sentences, explain why planetesimals had more material to grow from in the outer parts of the Solar Nebula than in the inner part.
31)In a few sentences, explain how the Jovian planets could begin with the accumulation of solid material and end by becoming surrounded by huge envelopes of hydrogen while the Terrestrial Planets began the same way but ended up different.
32)In a few sentences, explain why Saturn’s moon Titan has an atmosphere, but Earth’s moon does not even though both moons have nearly identical gravity fields and escape velocities.
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