Astronomy Exam 2: part 1
Energy and power are different words for the same thing. True False
False
Galaxies that show redshifts must be red in color. True False
False
Moons cannot have atmospheres, active volcanoes, or liquid water. True False
False
Our Moon is about the same size as moons of the other terrestrial planets. True False
False
Find the emitted power per square meter of peak intensity for a 50,000 K object that emits thermal radiation.
P = 3.56×10^-11 W/m^2
Find the emitted power per square meter of peak intensity for a 3000 K object that emits thermal radiation.
P = 4.62×10^6 W/m^2
Based on your study of the Interactive Figure, which of the following is not one of the four major features of the solar system? Swarms of asteroids and comets populate the solar system. Planets fall into two major categories (terrestrial and jovian). The solar system contains eight planets plus dwarf planets (including Ceres, Pluto, and Eris). Several exceptions to the general trends stand out. Large bodies in the solar system have orderly motions.
The solar system contains eight planets plus dwarf planets (including Ceres, Pluto, and Eris).
If a distant galaxy has a substantial redshift (as viewed from our galaxy), then anyone living in that galaxy would see a substantial redshift in a spectrum of the Milky Way Galaxy. True False
True
On average, Venus is the hottest planet in the solar system - even hotter than Mercury. True False
True
The weather conditions on Mars today are much different than they were in the distant past. True False
True
Suppose you start with 1 kilogram of a radioactive substance that has a half-life of 10 years. Which of the following statements will be true after 20 years pass? You'll have 0.75 kilogram of the radioactive substance remaining. You'll have 0.5 kilogram of the radioactive substance remaining. You'll have 0.25 kilogram of the radioactive substance remaining. All the material will have completely decayed.
You'll have 0.25 kilogram of the radioactive substance remaining.
What is a compound?
a molecule containing two or more elements
How much electrical charge does an atom with 6 protons, 6 neutrons, and 5 electrons have? a total charge of +17 a positive charge of +1 a negative charge of -5 a positive charge of +7 none of the above
a positive charge of +1
What is the Kuiper belt?
a region of the solar system beginning just beyond the orbit of Neptune that contains many icy comets
Recall that one of the laws of thermal radiation states that a higher-temperature object emits photons with higher average energy (Wien's law). This law is illustrated by the fact that for a higher temperature object, the graph peaks at __________. a shorter wavelength a longer wavelength a higher intensity
a shorter wavelength
A perfectly opaque object that absorbs all radiation and reemits the absorbed energy as thermal radiation is
a thermal emitter
If you heat a rock until it glows, its spectrum will be: a thermal radiation spectrum. an absorption line spectrum. an emission line spectrum.
a thermal radiation spectrum.
At which lunar phase(s) are tides least pronounced (e.g., the lowest high tides)? first quarter only full Moon new Moon both first and third quarters gibbous phase both new and full Moons
both first and third quarter
When we say that jovian planets contain significant amounts of hydrogen compounds, we mean all the following chemicals EXCEPT ______. carbon dioxide water methane ammonia
carbon dioxide
Compared to the Sun, a star whose spectrum peaks in the infrared is: cooler hotter larger
cooler
Pluto is different from the outer planets in all of the following ways except which one? it has few moons its orbit is not very close to being circular it doesn't have rings its surface temperature is very cold it is made mostly of ices
its surface temperature is very cold
Characteristics of Jovian Planets:
larger size low average density numerous orbiting moons extensive ring systems primarily composed of hydrogen, helium, and hydrogen compounds
Today, scientists have a theory (the nebular theory) that explains all the major characteristics of the solar system. In science, we expect a theory like this not only to explain the observed characteristics of our solar system but also to __________. make testable predictions about other solar systems predict which planets have life predict some major change that will eventually occur in our own solar system
make testable predictions about other solar systems
The frequency of a wave is measured in meters per second the same thing as the wavelength of a wave measured in meters measured in cycles per second B and C A, B, C and D are all true
measured in cycles per second
Sublimation is the process in which electrons are captured by ions molecules go from the solid phase to the gas phase molecules go from the liquid phase to the gas phase electrons are stripped from atoms molecules go from the solid phase to the liquid phase
molecules go from the solid phase to the gas phase
Thermal radiation is defined as
radiation that depends only on the emitting object's temperature.
A spectral line that appears at a wavelength of 321 nm in the laboratory appears at a wavelength of 328 nm in the spectrum of a distant object. We say that the object's spectrum is: redshifted. blueshifted. whiteshifted.
redshifted
Characteristics of Terrestial Planets:
small size located within the inner solar system solid rocky surface high average density
Sublimation is the process by which:
solid material enters the gas phase.
Which of the following is not an exception to the general patterns in the solar system? the large size of Earth's Moon the rings of Saturn the retrograde rotation of Triton around Neptune the extreme axis tilt of Uranus the counterclockwise rotation of Venus
the rings of Saturn
Uranium has atomic number 92. Its most common isotope is 238U, but the form used in nuclear bombs and nuclear power plants is 235U. How many neutrons are in each of these two isotopes of uranium?
238U contains 146 neutrons and 235U contains 143 neutrons
An atom of the element iron has an atomic number of 26 and an atomic weight of 56. If it is neutral, how many protons, neutrons, and electrons does it have?
26 protons, 30 neutrons, 26 electrons
An atom of the element iron has an atomic number of 26 and an atomic weight of 56. If it is neutral, how many protons, neutrons, and electrons does it have? 26 protons, 30 neutrons, 30 electrons 26 protons, 56 neutrons, 26 electrons 26 protons, 30 neutrons, 26 electrons 13 protons, 43 neutrons, 13 electrons 13 protons, 56 protons, 13 electrons
26 protons, 30 neutrons, 26 electrons
According to modern scientific dating techniques, approximately how old is the solar system? 10,000 years 4.5 billion years 14 billion years 4.6 million years
4.5 billion years
The Sun radiates a total power of about 4×1026 watts into space. The Sun's radius is about 7×108 meters. Calculate the average power radiated by each square meter of the Sun's surface. (Hint: The formula for the surface area of a sphere is A=4πr2.)
6×10^7 W/m^2
If two objects are the same size but one object is 3 times hotter than the other object, the hotter object emits 3 times more energy. 12 times more energy. 81 times more energy. 9 times more energy. none of the above
81 times more energy.
Which of the following statements about thermal radiation is always true? A hot object emits more total radiation than a cool object. A hot object emits less total radiation than a cool object. A hot object emits more total radiation per unit surface area than a cool object. A hot object emits more radio waves than a cool object. A hot object emits more X rays than a cool object.
A hot object emits more total radiation per unit surface area than a cool object.
Which of the following statements about thermal radiation is always true? A hot object emits photons with a higher average energy than a cool object. A hot object emits more X rays than a cool object. A hot object emits more radio waves than a cool object. A hot object emits photons with a longer wavelength than a cool object.
A hot object emits photons with a higher average energy than a cool object.
How does the spectrum of a molecule differ from the spectrum of an atom?
A molecule has additional spectral lines due to changes in its rotational and vibrational energies.
At extremely high temperatures (e.g., millions of degrees), which of the following best describes the phase of matter? A gas consisting of individual, neutral atoms, but no molecules A gas of rapidly moving molecules A plasma consisting of rapidly moving, neutral atoms A plasma consisting of positively charged ions and free electrons None of the above (At these extremely high temperatures, matter cannot exist.)
A plasma consisting of positively charged ions and free electrons
Which of the following statements about electrical charge is true? Two negative charges will attract each other. A positive charge and a negative charge will repel each other. Two positive charges will attract each other. A positive charge and a negative charge will attract each other.
A positive charge and a negative charge will attract each other.
How many Earths could fit inside Jupiter (assuming you could fill up all the volume)? The equation for the volume of a sphere is V=(43)πr3. (The radius of Jupiter is RJupiter = 71492 km.)
About 1410
How many Jupiters could fit inside the Sun? The equation for the volume of a sphere is V=(43)πr3.
About 919
Which jovian planet does NOT have rings?
All the jovian planets have rings.
Study the features relating to the first characteristic (orderly motions); click on the inner or outer solar system to see the planets in motion, then scroll over the planets to see diagrams of their axis tilts. Which of the following correctly describe patterns of motion in the solar system? The inner planets all rotate in the same direction (west to east) as Earth. All the planets (not counting Pluto) have nearly circular orbits. All the planets (not counting Pluto) orbit the Sun in nearly the same plane. The outer planets are so large that they nearly collide with each other on each orbit. Inner planets orbit the Sun in the opposite direction from the outer planets. Planets closer to the Sun move around their orbits at higher speed than planets farther from the Sun.
All the planets (not counting Pluto) have nearly circular orbits. All the planets (not counting Pluto) orbit the Sun in nearly the same plane. Planets closer to the Sun move around their orbits at higher speed than planets farther from the Sun.
Suppose you view the solar system from high above Earth's North Pole. Which of the following statements about planetary orbits will be true? All the planets orbit counterclockwise around the Sun. All the planets except Uranus orbit the Sun counterclockwise; Uranus orbits in the opposite direction. The inner planets orbit the Sun counterclockwise while the outer planets orbit the Sun clockwise. The inner planets orbit the Sun clockwise while the outer planets orbit the Sun counterclockwise.
All the planets orbit counterclockwise around the Sun.
When an atom absorbs a photon containing energy, any of the following can happen except which? The atom is ionized. An electron moves from a lower energy level to an upper one. An electron moves from an upper energy level to a lower one. The atom becomes excited.
An electron moves from an upper energy level to a lower one.
The dwarf planet Eris was discovered in 2005, orbiting the Sun at an average distance about twice that of Pluto. In which of the following ways do Pluto and Eris differ from the terrestrial and jovian planets in our solar system? Both Pluto and Eris are smaller than any of the terrestrial planets. Both Pluto and Eris travel in more elliptical orbits than any of the terrestrial or jovian planets. Both Pluto and Eris are denser than any of the terrestrial planets. Both Pluto and Eris are less massive than any of the terrestrial or jovian planets. Both Pluto and Eris have more hydrogen gas than any of the jovian planets.
Both Pluto and Eris are smaller than any of the terrestrial planets. Both Pluto and Eris travel in more elliptical orbits than any of the terrestrial or jovian planets. Both Pluto and Eris are less massive than any of the terrestrial or jovian planets.
The largest terrestrial planet and jovian planet are, respectively: Venus and Jupiter. Earth and Jupiter. Earth and Saturn.
Earth and Jupiter.
According to our theory of solar system formation, what three major changes occurred in the solar nebula as it shrank in size? Its gas clumped up to form the terrestrial planets, nuclear fusion produced heavy elements to make the jovian planets, and central temperatures rose to more than a trillion Kelvin. Its mass did NOT increase. Its mass, temperature, and density all increased. It got hotter, its rate of rotation increased, and it flattened into a disk.
It got hotter, its rate of rotation increased, and it flattened into a disk.
Which of the following statements about Pluto is true? Its mass is a little less than Earth's mass. It has more in common with comets in the Kuiper belt than it does with terrestrial planets like Earth. It is orbited by only one moon. It is the largest known object that is considered to be a dwarf planet.
It has more in common with comets in the Kuiper belt than it does with terrestrial planets like Earth.
What do we mean by the frost line when we discuss the formation of planets in the solar nebula? It marks the special distance from the Sun at which hydrogen compounds become abundant; closer to the Sun, there are no hydrogen compounds. It is the altitude in a planet's atmosphere at which snow can form. It is another way of stating the temperature at which water freezes into ice. It is a circle at a particular distance from the Sun, beyond which the temperature was low enough for ices to condense.
It is a circle at a particular distance from the Sun, beyond which the temperature was low enough for ices to condense.
How can an electron in an atom lose energy to go from a higher energy level to a lower energy level? It loses kinetic energy. It absorbs a photon equal in energy to its own energy drop. It releases a photon equal in energy to its own energy drop. It loses gravitational potential energy. It exchanges gravitational potential energy for kinetic energy.
It releases a photon equal in energy to its own energy drop.
What is the Oort cloud?
It's not really a cloud at all, but rather refers to the trillion or so comets thought to orbit the Sun at great distances.
Now consider the second major characteristic (two types of planets). Which of the following statements are true? Jovian planets are larger in mass than terrestrial planets. Jovian planets have more moons than terrestrial planets. Jovian planets are larger in size than terrestrial planets. Jovian planets are higher in average density than terrestrial planets. Jovian planets orbit farther from the Sun than terrestrial planets.
Jovian planets are larger in mass than terrestrial planets. Jovian planets have more moons than terrestrial planets. Jovian planets are larger in size than terrestrial planets. Jovian planets orbit farther from the Sun than terrestrial planets.
According to our theory of solar system formation, what are asteroids and comets? Chunks of rock or ice that condensed after the planets and moons finished forming Leftover planetesimals that never accreted into planets The shattered remains of collisions between planets Chunks of rock or ice that were expelled from planets by volcanoes
Leftover planetesimals that never accreted into planets
Which of the following is not a pattern of motion in our solar system? Planets all orbit the same direction as the Sun's spin. Large planets all have many moons orbiting them. Planets all orbit in the same direction. Planets all rotate in the same direction.
Planets all rotate in the same direction.
Assuming that other planetary systems form in the same way as our solar system formed, where would you expect to find terrestrial planets?
Terrestrial planets will likely be located nearer the planetary system's star than any jovian planets.
What is the giant impact hypothesis for the origin of the Moon? The Moon formed just like Earth, from accretion in the solar nebula. The Moon formed when two gigantic asteroids collided with one another. The Moon formed from material blasted out of Earth's mantle and crust by the impact of a Mars-size object. The Moon originally was about the same size as Earth, but a giant impact blasted most of it away so that it ended up much smaller than Earth.
The Moon formed from material blasted out of Earth's mantle and crust by the impact of a Mars-size object.
Which of the following statements about our Sun is NOT true? The Sun's diameter is about five times that of Earth. The Sun contains more than 99 percent of all the mass in our solar system. The Sun is made mostly of hydrogen and helium. The Sun is a star.
The Sun's diameter is about five times that of Earth.
Consider an atom of gold in which the nucleus contains 79 protons and 118 neutrons. What is its atomic number and atomic weight? The atomic number is 118, and the atomic weight is 79. The atomic number is 79, and the atomic weight is 118. The atomic number is 118, and the atomic weight is 197. The atomic number is 79, and the atomic weight is 197.
The atomic number is 79, and the atomic weight is 197.
Suppose you see two stars: a blue star and a red star. Which of the following can you conclude about the two stars? Assume that no Doppler shifts are involved. (Hint: Think about the laws of thermal radiation.) The blue star is more massive than the red star. The red star is more massive than the blue star. The blue star is farther away than the red star. The red star has a hotter surface temperature than the blue star. The blue star has a hotter surface temperature than the red star.
The blue star has a hotter surface temperature than the red star.
Consider an atom of gold in which the nucleus contains 79 protons and 118 neutrons. If it is doubly ionized, what is the charge of the gold ion and how many electrons remain in the ion? The gold ion has a charge of +2 and 77 electrons. The gold ion has a charge of +79 and no electrons. The gold ion has a charge of +2 and 2 electrons. The gold ion has a charge of -2 and 77 electrons. The gold ion has a charge of +2 and 79 electrons.
The gold ion has a charge of +2 and 77 electrons.
You observe the same spectral line in two stars that are identical in every way except that one rotates faster than the other. How does the spectral line differ between the two? There is no difference. The line in the faster rotating star is narrower. The line in the faster rotating star is blueshifted. The line in the faster rotating star is redshifted. The line in the faster rotating star is broader.
The line in the faster rotating star is broader.
If one object has a large redshift and another object has a small redshift, what can we conclude about these two objects? The one with the large redshift is redder than the other one. The one with the large redshift is hotter and therefore is putting out more radiation. The one with the large redshift is moving away from us, and the one with the small redshift is moving toward us. The one with the large redshift is moving toward us faster than the one with the small redshift. The one with the large redshift is moving away from us faster than the one with the small redshift.
The one with the large redshift is moving away from us faster than the one with the small redshift.
If we observe one edge of a planet to be redshifted and the opposite edge to be blueshifted, what can we conclude about the planet? The planet is actually two bodies, one moving toward us, the other away from us. The planet's surface is very different from one side to the other. The planet is in the process of formation. The planet is in the process of falling apart. The planet is rotating.
The planet is rotating.
Consider only the observed patterns of motion in the solar system. Scientifically, which of the following possible conclusions is justified from the patterns of motion alone? The planets were not born within the past million years, but instead they must have been born billions of years ago. The planets started out quite small and grew to their current sizes as they gradually accreted more material. The planets were born from a giant cloud of gas that rotated in the same direction that the Milky Way Galaxy rotates. The planets were not each born in a separate, random event.
The planets were not each born in a separate, random event.
From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 121.6 nanometers (nm). The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 121.8 nm. What can we conclude? The star is moving away from us. The star is moving toward us. The "star" actually is a planet. The star is getting hotter. The star is getting colder.
The star is moving away from us.
We can learn a lot about the properties of a star by studying its spectrum. All of the following statements are true except one. Which one? The peak of the star's thermal emission tells us its temperature: Hotter stars peak at shorter (bluer) wavelengths. We can look at Doppler shifts of spectral lines to determine the star's speed toward or away from us. The total amount of light in the spectrum tells us the star's radius. We can identify chemical elements present in the star by recognizing patterns of spectral lines that correspond to particular chemicals.
The total amount of light in the spectrum tells us the star's radius.
Which of the following is not a characteristic of the inner planets? They have very few, if any, satellites. They are relatively smaller than the outer planets. Their orbits are relatively closely spaced. They all have substantial atmospheres. They all have solid, rocky surfaces.
They all have substantial atmospheres.
Which of the following is not a characteristic of the outer planets? They have very few, if any, satellites. They are primarily made of hydrogen and helium. Their orbits are separated by relatively large distances. They all have rings. They are all large balls of gas.
They have very few, if any, satellites.
All the following statements are true. Which of them are considered to be "exceptions" to the general trends described by the first three major characteristics of the solar system?
Uranus rotates with an axis tilt that lies nearly in the ecliptic plane. Our Moon has a diameter more than 1/4 the diameter of Earth. Venus rotates in a direction opposite to the rotation of the other terrestrial planets
Which planet is approximately halfway between Pluto's orbit and the Sun? Mars, the fourth planet from the Sun Jupiter, the fifth planet from the Sun Saturn, the sixth planet from the Sun Uranus, the seventh planet from the Sun
Uranus, the seventh planet from the Sun
The planet in our solar system with the highest average surface temperature is Mercury Neptune Earth Venus
Venus
The planet in our solar system with the highest average surface temperature is __________.
Venus
Are there any exceptions to the rule that planets rotate with small axis tilts and in the same direction that they orbit the Sun? No. Venus is the only exception. Venus, Uranus, and Pluto are exceptions.
Venus, Uranus, and Pluto are exceptions.
Which terrestrial planets have had volcanic activity at some point in their histories?
all of them
Suppose you view the solar system from high above Earth's North Pole. Which of the following statements about planetary orbits will be true? all the planets except Uranus orbit the Sun counterclockwise; Uranus orbits in the opposite direction the inner planets orbit the Sun clockwise while the outer planets orbit the Sun counterclockwise all the planets orbit counterclockwise around the Sun the inner planets orbit the Sun counterclockwise while the outer planets orbit the Sun clockwise
all the planets orbit counterclockwise around the Sun
What type of visible light spectrum does the Sun produce? a continuous spectrum an absorption line spectrum an emission line spectrum
an absorption line spectrum
An electron-volt is
an amount of energy much smaller than a joule.
If you heat a gas so that collisions are continually bumping electrons to higher energy levels, when the electrons fall back to lower energy levels the gas produces an emission line spectrum X rays radio waves an absorption line spectrum thermal radiation
an emission line spectrum
If you heat a gas so that collisions are continually bumping electrons to higher energy levels, when the electrons fall back to lower energy levels the gas produces X rays. radio waves. an emission line spectrum. an absorption line spectrum. thermal radiation.
an emission line spectrum.
Which of the following three kinds of objects resides closer to the Sun on average? comets asteroids jovian planets
asteroids
Consider an atom of carbon in which the nucleus contains 6 protons and 7 neutrons. What is its atomic number and atomic mass number? atomic number=7; atomic mass number=13 atomic number=13; atomic mass number=6 atomic number=6, atomic mass number=7 atomic number=6; atomic mass number=13
atomic number=6; atomic mass number=13
The absorption line spectrum shows what we see when we look at a hot light source (such as a star or light bulb) directly behind a cooler cloud of gas. Suppose instead that we are looking at the gas cloud but the light source is off to the side instead of directly behind it. In that case, the spectrum would __________. be an emission spectrum appear completely dark still be an absorption spectrum appear as a continuous rainbow of colors
be an emission spectrum
When an electron in an atom goes from a higher energy state to a lower energy state, the atom can emit a photon of any frequency can absorb a photon of any frequency absorbs several photons of a specific frequency emits a photon of a specific frequency absorbs a photon of a specific frequency
emits a photon of a specific frequency
Planetary orbits are: very eccentric (stretched-out) ellipses and in the same plane. fairly circular and in the same plane. fairly circular but oriented in every direction.
fairly circular and in the same plane.
The spectra of most galaxies show redshifts. This means that their spectral lines _________. always are in the red part of the visible spectrum have wavelengths that are shorter than normal have wavelengths that are longer than normal have a higher intensity in the red part of the spectrum
have wavelengths that are longer than normal
Which of the following objects is not a close approximation of a thermal emitter? hot, thin gas you a filament in a light bulb a planet a star
hot, thin gas
What are the main constituents of the jovian planets? nitrogen and methane rocky minerals and water, as on Earth ammonia and methane ammonia and water hydrogen and helium
hydrogen and helium
Compared to an atom as a whole, an atomic nucleus: is very tiny but has most of the mass. is quite large and has most of the mass. is very tiny and has very little mass.
is very tiny but has most of the mass.
Some nitrogen atoms have seven neutrons and some have eight neutrons. These two forms of nitrogen are: ions of each other. phases of each other. isotopes of each other.
isotopes of each other.
What is the Oort cloud? it is a giant storm in the atmosphere of Saturn it is a giant cloud of gas that resides far beyond the orbit of Pluto it is another name for the cloud of gas from which our solar system was born it is not really a cloud at all, but rather refers to the trillion or so comets thought to orbit the Sun at great distances
it is not really a cloud at all, but rather refers to the trillion or so comets thought to orbit the Sun at great distances
Grass (that is healthy) looks green because it emits green light and absorbs other colors it reflects green light and absorbs other colors it absorbs green light and emits other colors it reflects green light and emits other colors
it reflects green light and absorbs other colors
Compared to terrestrial planets, jovian planets are __________. more massive and higher in average density more massive and lower in average density less massive and lower in average density less massive and higher in average density
more massive and lower in average density
Large moons orbit their planets in the same direction the planet rotates:
most of the time.
Which of the following statements is not an observed pattern of motion in our solar system? most planets orbit at the same speed most planets rotate in the same direction in which they orbit almost all moons orbit their planet in the same direction as the planet's rotation all planets orbit the Sun in the same direction Most planetary orbits lie nearly in the same plane
most planets orbit at the same speed
A gas heated to millions of degrees would emit
mostly X rays.
Light with a short wavelength is redder than light with a longer wavelength has a lower frequency than light with a longer wavelength has photons with less energy than light with a longer wavelength all of the above none of the above
none of the above
Approximately where it is currently high tide on Earth? anywhere that ocean water laps upon the shore wherever it is currently noon only on the portion of the Earth facing directly toward the Moon on the portion of Earth facing directly toward the Moon and on the portion of Earth facing directly away from the Moon
on the portion of Earth facing directly toward the Moon and on the portion of Earth facing directly away from the Moon
Ceres, the largest asteroid, has an orbital semimajor axis of 2.77 AU. Use Kepler's third law to find its orbital period.
p = 4.61 yr
When considering light as made up of individual "pieces," each characterized by a particular amount of energy, the pieces are called gamma rays frequencies photons wavicles
photons
Now consider why the observed patterns of motion lead to the conclusion that the planets were not born in separate, random events. The reason for this conclusion is that, if the planets had been born in separate, random events, we would expect that __________. planetary orbits would have many different orientations and directions, rather than all being in the same direction and in the same plane planets would orbit at much higher speeds than they actually do there would be many different types of planets, rather than just two major types none of the planets would have ended up with moons
planetary orbits would have many different orientations and directions, rather than all being in the same direction and in the same plane
Which of the following is not a major difference between the terrestrial and jovian planets in our solar system? terrestrial planets orbit much closer to the Sun then jovian planets terrestrial planets contain large quantities of ice and jovian planets do not jovian planets have rings and terrestrial planets do not terrestrial planets are higher in average density than jovian planets
terrestrial planets contain large quantities of ice and jovian planets do not
Astronomers have decided that, rather than being a planet, Pluto is really just a large member of the Kuiper belt an extrasolar planetary system the asteroid belt the Oort cloud the moon system around Neptune
the Kuiper belt
Which of the following best explains why the Moon's orbital period and rotation period are the same? the law of conservation of angular momentum ensured that the Moon must have the same amount of rotational angular momentum as it has of orbital angular momentum the equality of the Moon's orbital and rotation periods is an extraordinary astronomical coincidence the Moon once rotated fast, but tidal friction slowed the rotation period until it matched the orbital period the Moon was once closer to Earth, but the force of gravity got weaker as the Moon moved farther away
the Moon once rotated fast, but tidal friction slowed the rotation period until it matched the orbital period
The solar system contains vast numbers of small bodies, which we call asteroids when they are rocky and comets when they are icy. These small bodies are concentrated in the region(s) of the solar system that we call __________. the comet belt the solar corona the Oort cloud the Doppler belt the asteroid belt the Kuiper belt
the Oort cloud the asteroid belt the Kuiper belt
Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space? the cloud is extremely hot the loud is cool and very dense, so that you cannot see any objects that lie behind it the could is visible primarily because it reflects light from nearby stars the cloud is cool and lies between you and a hot star
the cloud is cool and lies between you and a hot star
The following statements are all true. Which one counts as an "exception to the rule" in being unusual for our solar system? Saturn has no solid surface the diameter of Earth's Moon is about 1/4 that of Earth Jupiter has a very small axis tilt Venus does not have a moon
the diameter of Earth's Moon is about 1/4 that of Earth
Which of the following is not an exception to the general patterns in the solar system? the retrograde rotation of Triton around Neptune the large size of Earth's Moon the extreme axis tilt of Uranus the counterclockwise rotation of Venus the rings of Saturn
the rings of Saturn
Suppose you want to know the chemical composition of a distant star. Which piece of information is most useful to you? Whether the star's spectrum has more emission lines or more absorption lines The wavelengths of spectral lines in the star's spectrum The peak energy of the star's thermal radiation The Doppler shift of the star's spectrum
the wavelengths of spectral lines in the star's spectrum
Which of the following is not a characteristic of the inner planets? their obits are relatively closely spaced they all have substantial atmospheres they all have solid, rocky surfaces they are relatively smaller than the outer planets they have very few, if any, satellites
they all have substantial atmospheres
Which travels fastest? radio waves visible light X rays ultraviolet light they all travel at the same speed
they all travel at the same speed
Suppose you watch a leaf bobbing up and down as ripples pass it by in a pond. You notice that it does four full up and down bobs each second. Which statement is true of the ripples on the pond? we can calculate the wavelength of the ripples from their frequency they have a frequency of 4 hertz they have a frequency of 2 hertz they have a wavelength of four cycles per second
they have a frequency of 4 hertz
Which of the following best describes the fundamental difference between two different chemical elements (such as oxygen and carbon)? they have different numbers of protons in their nucleus they have different numbers of electrons they have different atomic mass numbers they have different names
they have different numbers of protons in their nucleus
Which of the following best describes the origin of ocean tides on Earth? tides are caused by the 23 1/2° tilt of the earth's rotational axis to the ecliptic plane tides are caused only on the side of Earth nearest the Moon because the Moon's gravity attracts the water on that side and not on the other side tides are caused primarily by the gravitational force of the Sun the Moon's gravity pulls harder on water than on land, because water is less dense than rock tides are caused by the difference in the force of gravity exerted by the Moon across the sphere of the earth
tides are caused by the difference in the force of gravity exerted by the Moon across the sphere of the earth
Find the wavelength of peak intensity for a 50,000 K object that emits thermal radiation.
λ peak = 58.0 nm
Find the wavelength of peak intensity for a 3000 K object that emits thermal radiation.
λ peak = 967 nm