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117 Cards in this Set
- Front
- Back
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Suppose you have a 100-watt light bulb that you leave turned on for one minute. How much energy does it use?
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6,000 joules
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Which of the following statements is true of green grass?
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It absorbs red light and reflects green light
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Suppose you are listening to a radio station that broadcasts at a frequency of 97 Mhz (megahertz). Which of the following statements is true?
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The radio waves from the radio station are causing electrons in your radio's antenna to move up and down 97 million times each second.
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Gamma rays have a very small ______
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wavelength
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Suppose a photon has a frequency of 300 million hertz (300 megahertz). What is its wavelength?
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1 meter
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Which of the following best describes why we say that light is an electromagnetic wave?
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The passage of a light wave can cause electrically charged particles to move up and down.
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Which of the following statements about X rays and radio waves is not true?
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X rays travel through space faster than radio waves.
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Each of the following describes an "Atom 1" and an "Atom 2." In which case are the two atoms different isotopes of the same element?
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Atom 1: nucleus with 7 protons and 8 neutrons, surrounded by 7 electrons; Atom 2: nucleus with 7 protons and 7 neutrons, surrounded by 7 electrons
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Suppose you had molecular oxygen (O2) chilled enough so that it was in liquid form. Which of the following best describes the phase changes that would occur as you heated the liquid oxygen to high temperature?
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It would evaporate into a gas, then the molecules would dissociate into individual oxygen atoms, then the atoms would become increasingly ionized as you continued to raise the temperature.
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Consider an atom of oxygen in which the nucleus contains 8 protons and 8 neutrons. If it is doubly ionized, what is the charge of the oxygen ion and how many electrons remain in the ion?
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Charge = +2; number of remaining electrons = 6.
Because oxygen has 8 protons, it is neutral if it also has 8 electrons |
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Which of the following statements about electrons is not true?
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Electrons orbit the nucleus rather like planets orbiting the Sun.
electrons are not like tiny planets at all |
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Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space?
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The cloud is cool and lies between you and a hot star.
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No object produces a perfect thermal radiation spectrum, but many objects produce close approximations. Which of the following would not produce a close approximation to a thermal radiation spectrum?
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a hot, thin (low-density, nearly transparent) gas
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Which of the following statements about thermal radiation is always true?
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A hot object emits more radiation per unit surface area than a cool object.
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Betelgeuse is the bright red star representing the left shoulder of the constellation Orion. All the following statements about Betelgeuse are true. Which one can you infer from its red color?
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Its surface is cooler than the surface of the sun
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The planet Neptune is blue in color. How would you expect the spectrum of visible light from Neptune to be different from the visible-light spectrum of the Sun?
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The two spectra would have similar shapes, except Neptune's spectrum would be missing a big chunk of the red light that is present in the Sun's spectrum.
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All of the following statements about the Sun's corona are true. Which one explains why it is a source of X rays?
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The temperature of the corona's gas is some 1 to 2 million Kelvin.
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Laboratory measurements show hydrogen produces a spectral line at a wavelength of 486.1 nanometers (nm). A particular star's spectrum shows the same hydrogen line at a wavelength of 486.0 nm. What can we conclude?
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The star is moving towards us.
The overall Doppler shift of a spectrum has nothing to do with an object's temperature |
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Suppose that Star X and Star Y both have redshifts, but Star X has a larger redshift than Star Y. What can you conclude?
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Star X is moving away from us faster than Star Y.
The redshifts mean that both stars are moving away from us, and a larger redshift means a faster speed. |
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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?
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the planet is rotating
we see a blueshift from the side rotating toward us and a red shift from the side rotating away |
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Studying a spectrum from a star can tell us a lot. All of the following statements are true except one. Which statement is not true?
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The total amount of light in the spectrum tells us the star's radius.
We cannot measure radius from a spectrum without additional info |
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Suppose that two stars are identical in every way - for example, same distance, same mass, same temperature, same chemical composition, and same speed relative to Earth - except that one star rotates faster than the other. Spectroscopically, how could you tell the stars apart?
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The faster rotating star has wider spectral lines than the slower rotating star.
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Why does the Sun’s image look distorted in shape at sunset?
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The distortion arises because of the way air affects the paths of light.
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Suppose you have a camera attached to a telescope, and you want to record an image of a very faint galaxy. Which of the following will help the most?
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a lot of pixels and a long exposure time
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Suppose you have two small photographs of the Moon. Although both look the same at small size, when you blow them up to poster size one of them still looks sharp while the other one becomes fuzzy (grainy) looking. Which of the following statements is true?
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The one that still looks sharp at large size has better (smaller) angular resolution than the one that looks fuzzy.
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The angular separation of two stars is 0.1 arcseconds and you photograph them with a telescope that has an angular resolution of 1 arcsecond. What will you see?
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The photo will seem to show only one star rather than two.
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How does the light-collecting area of an 8-meter telescope compare to that of a 2-meter telescope?
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The 8-meter telescope has 16 times the light-collecting area of the 2-meter telescope.
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Which of the following best describes the development of astronomical telescopes over the past 65 years?
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The world's most powerful telescope remained the same for most of this period, but in the past 20 years many new and more powerful telescopes have been built.
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Which of the following best describes why radio telescopes are generally much larger in size than telescopes designed to collect visible light?
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Getting an image of the same angular resolution requires a much larger telescope for radio waves than for visible light.
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Which of the following studies is best suited to astronomical observations that fall into the category called time monitoring?
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Studying how a star's brightness varies over a period of 3 years.
time monitoring allows us yo measure changes in time |
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Which of the following is not a reason why telescopes tend to be built on mountaintops that are relatively far from cities and are in regions with dry climates?
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The thin air on mountaintops makes the glass in telescope mirrors less susceptible to warping
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The stars in our sky twinkle in brightness and color because of ______.
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turbulence in the Earth's atmosphere
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Which of the following is not an advantage of the Hubble Space Telescope over ground-based telescopes?
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It is closer to the stars
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The Chandra X-ray Observatory must operate in space because:
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X rays do not penetrate Earth's atmosphere
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Which of the following telescopes benefits most from adaptive optics?
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The Keck I telescope on Mauna Kea
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Consider two future observatories in space. Observatory X consists of a single 50-meter telescope. Observatory Y is an interferometer consisting of five 10-meter telescopes, spread out over a region 100 meters across. Which observatory can detect dimmer stars, and which one can see more detail in its images? (Assume all else is equal, such as quality of optics, types of instruments, and so on.)
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Observatory X can detect dimmer stars and Observatory Y reveals more detail in images.
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Why can’t X-ray and gamma-ray telescopes use the same designs as visible-light telescopes?
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X rays and gamma rays have so much energy that they cannot be reflected in the same way as visible light.
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Which of the following is not a major pattern of motion in the solar system?
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Nearly all comets orbit the Sun in same direction and roughly the same plane.
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Which of the following is not a major difference between the terrestrial and jovian planets in our solar system?
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Terrestrial planets contain large quantities of ice and jovian planets do not.
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Consider the following statement: "Rocky asteroids are found primarily in the asteroid belt and Kuiper belt while icy comets are found primarily in the Oort cloud." What's wrong with this statement?
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The Kuiper belt contains icy comets, not rocky asteroids.
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Which of the following is not a real difference between asteroids and comets?
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Asteroids orbit the Sun while comets just float randomly around in the Oort cloud.
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The following statements are all true. Which one counts as an "exception to the rule" in being unusual for our solar system?
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The diameter of Earth's Moon is about 1/4 that of Earth.
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Compared to the distance between Earth and Mars, the distance between Jupiter and Saturn is ______.
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much larger
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How is Einstein's famous equation, E=mc2, important in understanding the Sun?
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It explains the fact that the Sun generates energy to shine by losing some 4 million tons of mass each day.
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Venus has a higher average surface temperature than Mercury. Why?
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Because its surface is heated by an extreme greenhouse effect
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In what way is Venus most similar to Earth?
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both planets are nearly the same size
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Which of the following statements about the object called Eris is not true?
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It is thought to be the first example of a new class of object
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mars has two moons that are most similar in character to
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small asteroids
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Imagine that an alien spaceship crashed onto Earth. Which statement would most likely be true?
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It would crash in the ocean
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which planet listed below has the most extreme seasons
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Uranus
it essentially rotates on its side compared to its orbit, giving it very extreme seasons |
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in what way is pluto more like a comet than a planet?
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it is made mostly of rock and ice
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why was it advantageous for the Voyager mission to consist of flybys rather than orbiters
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each individual spacecraft was able to visit more than one planet
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Why has NASA sent recent orbiters to Mars (such as Mars Reconnaissance Orbiter) on trajectories that required them to skim through Mars's atmosphere before settling into their final orbits?
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It saves money because the spacecraft uses atmospheric drag to slow down rather than needing to carry enough fuel to slow by firing rocket engines.
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Which of the following best explains why we can rule out the idea that planets are usually formed by near-collisions between stars?
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Stellar near-collisions are far too rare to explain all the planets now known to orbit nearby stars.
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According to our modern science, which of the following best explains why the vast majority of the mass of our solar system consists of hydrogen and helium gas?
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Hydrogen and helium are the most common elements throughout the universe, because they were the only elements present when the universe was young.
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According to our theory of solar system formation, which law best explains why the central regions of the solar nebula got hotter as the nebula shrank in size?
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the law of conservation of energy
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According to our theory of solar system formation, which law best explains why the solar nebula spun faster as it shrank in size?
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The law of conservation of angular momentum
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According to our present theory of solar system formation, which of the following best explains why the solar nebula ended up with a disk shape as it collapsed?
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It flattened as a natural consequence of collisions between particles in the nebula.
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What is the primary basis upon which we divide the ingredients of the solar nebula into four categories (hydrogen/helium; hydrogen compound; rock; metal)?
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The temperatures at which various materials will condense from gaseous form to solid form.
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According to our present theory of solar system formation, which of the following statements about the growth of terrestrial and jovian planets is not true?
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The jovian planets began from planetesimals made only of ice, while the terrestrial planets began from planetesimals made only of rock and metal.
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Many meteorites appear to have formed very early in the solar system's history. How do these meteorites support our theory about how the terrestrial planets formed?
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The meteorites appearance and composition is just what we'd expect if metal and rock condensed and accreted as our theory suggests.
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According to present understanding, which of the following statements about the solar wind is not true?
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It is even stronger today than it was when the Sun was young
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According to our present theory of solar system formation, how did Earth end up with enough water to make oceans?
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The water was brought to the forming Earth by planetesimals that accreted beyond the orbit of Mars.
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What is the primary reason that astronomers suspect that some jovian moons were captured into their current orbits?
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Some moons have orbits that are "backwards" (compared to their planet's rotation) or highly inclined to their planet's equator.
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Which of the following is not a line of evidence supporting the hypothesis that our Moon formed as a result of a giant impact?
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The Pacific Ocean appears to be a large crater - probably the one made by the giant impact.
The Pacific Ocean is not an impact crater. Moreover, since the continents are rearranged with time, we can be sure that the giant impact occurred long, long before there was a Pacific Ocean. |
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Why are terrestrial planets denser than jovian planets?
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The terrestrial planets formed in the inner solar nebula, where only dense materials could condense.
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Suppose you find a rock that contains 10 micrograms of radioactive potassium-40, which has a half-life of 1.25 billion years. By measuring the amount of its decay product (argon-40) present in the rock, you conclude that there must have been 80 micrograms of potassium-40 when the rock solidified. How old is the rock?
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3.75 billion years
The current 10 micrograms of potassium-40 is 1/8 of the original 80 grams, which means the amount of potassium-40 has declined by a factor of 8. Therefore, three half-lives have passed (since 23 = 8) and the rock is 3(1.25 = 3.75 billion years old. |
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How do scientists determine the age of the solar system?
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Radiometric dating of meteorites
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The region of our solar system between Mercury and Mars has very few asteroids, while the region between Mars and Jupiter has many asteroids. Based on what you have learned, what is the most likely explanation for the lack of asteroids between Mercury and Mars?
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There were very few planetary leftovers in this region, because most of the solid material was accreted by the terrestrial planets as the planets formed
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About 2% of our solar nebula consisted of elements besides hydrogen and helium. However, the very first generation of star systems in the universe probably consisted only of hydrogen and helium. Which of the following statements is most likely to have been true about these first-generation star systems?
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There were no comets or asteroids in these first-generation star systems.
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The cores of the terrestrial worlds are made mostly of metal because ______.
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metals sunk to the centers a long time ago when the interiors were molten throughout
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Which of the following is not generally true of all the terrestrial world lithospheres?
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The lithosphere is broken into a set of large plates that float upon the softer rock below.
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Which internal heat source still generates heat within the terrestrial worlds today?
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heat from radioactive decay
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The reason that small planets tend to lose interior heat faster than larger planets is essentially the same as the reason that ________.
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a large baked potato takes longer to cool than a small baked potato
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Suppose we had a device that allowed us to see Earth's interior. If we looked at a typical region of the mantle, what would we see happening?
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not much - on human time scales, the mantle looks like solid rock
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Recent evidence suggests that Mars once had a global magnetic field. Assuming this is true, which of the following could explain why Mars today lacks a global magnetic field like that of Earth?
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Mars's interior has cooled so much that its molten core layer no longer undergoes convection.
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Which of the following most likely explains why Venus does not have a global magnetic field like Earth?
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its rotation is too slow
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You discover an impact crater that is 10 kilometers across. Which of the following can you conclude?
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it was created by the impact of an object about 1 km across
impact craters are typically 10 times as wide as the objects that create them |
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Most of the Moon's surface is densely covered with craters, but we find relatively few craters within the lunar maria. What can we conclude?
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the maria formed after the heavy bombardment ended
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which of the following is the underlying reason why Venus has so little wind erosion?
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its slow rotation
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which of the following best describes the geological histories of the moon and mercury
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early in their histories, they suffered many impacts and experienced some volcanism and tectonics, but they now have little geological activity at all
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Many scientists suspect that Venus has a stronger and thicker lithosphere than Earth. If this is true, which of the following could explain it?
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The high surface temperature that has "baked out" all the liquid water from Venus's crust and mantle.
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All the following statements about Venus are true. Which one offers evidence of a global repaving about a billion years ago?
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Venus has relatively few impact craters and these craters are distributed fairly evenly over the entire planet.
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What are the two geological features that appear to set Earth apart from all the other terrestrial worlds?
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plate tectonics and widespread erosion
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Why are there fewer large impact craters on the Earth's seafloor than on the continents?
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Seafloor crust is younger than continental crust, so it has had less time in which to suffer impacts.
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Why is Earth's continental crust lower in density than seafloor crust?
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Continental crust is made as the lowest-density seafloor crust melts and erupts to the surface near subduction zones.
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Which two factors are most important to the existence of plate tectonics on Earth?
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mantle convection and a thin lithosphere
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What's the fundamental reason that Mars, unlike the Earth, has become virtually geologically dead?
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its small size compared to Earth
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Based on all we know about the terrestrial worlds, what single factor appears to play the most important role in a terrestrial planet's geological destiny?
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its size
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The choices below describe four hypothetical planets. Which one would you expect to have the hottest interior? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.)
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Size: twice as big as Earth. Distance from Sun: same as Mercury. Rotation rate: once every 6 months.
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The choices below describe four hypothetical planets. Which one's surface would you expect to be most crowded with impact craters? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.)
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Size: same as the Moon. Distance from Sun: same as Mars. Rotation rate: once every 10 days.
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The choices below describe four hypothetical planets. Which one would you expect to have the most features of erosion? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.)
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Size: same as Venus. Distance from Sun: same as Mars. Rotation rate: once every 25 hours.
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Which of the following general statements about Earth's atmosphere is not true?
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The sea level temperature depends primarily on the total amount of gas in our atmosphere.
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Suppose that Earth's ice caps melted, but everything else about the Earth's surface and atmosphere stayed the same. What would happen to Earth's average surface temperature?
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The surface temperature would increase
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Which of the following best describes how the greenhouse effect works?
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A planet's surface absorbs visible sunlight and returns this absorbed energy to space as infrared light. Greenhouse gases slow the escape of this infrared radiation, which thereby heats the lower atmosphere.
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All the statements below are true. Which one gives the primary reason why the surface of Venus today is some 450°C hotter than the surface of Earth?
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Venus has a much stronger greenhouse effect than Earth.
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Which of the following statements about Earth's troposphere is not generally true?
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It is the layer of the atmosphere in which ozone absorbs dangerous ultraviolet light from the Sun.
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In very general terms, how do the temperature structures of the atmospheres of Venus and Mars differ from that of Earth?
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They lack ultraviolet-absorbing stratospheres.
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Does Venus have auroras around its poles, like Earth? Why or why not?
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No, because it lacks a global magnetic field.
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All the following statements are true. Which one explains why convection can occur in the troposphere but not in the stratosphere?
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Temperature declines with altitude in the troposphere but increases with altitude in the stratosphere.
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Which of the following is not caused by the Coriolis effect on Earth?
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Water going down a drain swirls in opposite directions in the northern and southern hemispheres.
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Why is the Coriolis effect so weak on Venus?
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because venus rotates so slowly
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All of the following have occurred over long periods of time on Earth. Which one is not thought to have played a major role in long-term changes in Earth's climate?
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A gradual rise in the atmospheric content of oxygen
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Why do we think that Venus has so much more atmospheric gas than Earth?
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Most of the gases that have been released from volcanoes on Earth later returned to the surface.
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Why is thermal escape of atmospheric gas much easier from the Moon than from Earth?
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Because the Moon's gravity is so much weaker than Earth's.
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Observations indicate that the Moon has water ice in craters near the poles. Where do scientists suspect this water came from?
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ice brought by comet impacts long ago
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All the following statements about Mars are true. Which one might have led to a significant loss of atmospheric gas to space?
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Mars lost any global magnetic field that it may once have had.
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What makes us think that Mars must once have had an atmosphere that was warmer and had higher surface pressure?
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The atmosphere is too cold and thin for liquid water today, yet we see evidence of flowing water in the past.
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Which of the following best explain what we think happened to outgassed water vapor on Venus?
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Ultraviolet light split the water molecules, and the hydrogen then escaped to space.
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What would happen to Earth if we somehow moved our planet to the orbit of Venus
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Earth would suffer a runaway greenhouse effect and become as hot or hotter than Venus.
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Deuterium is much more abundant on Venus than Earth. What do we think this fact tells us about Venus?
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That it has lost a tremendous amount of water as a result of molecules being split by ultraviolet light and the hydrogen escaping to space.
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Why does Earth have so little carbon dioxide in its atmosphere compared to Venus?
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Earth has just as much carbon dioxide as Venus, but most of it is locked up in carbonate rocks rather than being free in the atmosphere.
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Which characteristic of Earth explains why we have an ultraviolet-absorbing stratosphere?
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the existence of photosynthetic life
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Which two factors are critical to the existence of the carbon dioxide (CO2) cycle on Earth?
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plate tectonics and liquid water oceans
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Suppose Earth were to cool down a little. How would the carbon dioxide cycle tend to restore temperatures to normal?
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Cooler temperatures lead to slower formation of carbonate minerals in the ocean, so carbon dioxide released by volcanism builds up in the atmosphere and strengthens the greenhouse effect.
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According to current science, why didn't oxygen begin to accumulate in the atmosphere for more than a billion years after life appeared on the Earth?
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Oxygen released by life was removed from the atmosphere by chemical reactions with surface rocks until the surface rock could absorb no more.
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Earth has been gradually warming over the past few decades. Based on a great deal of evidence, scientists believe that this warming is caused by _____.
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human activities that are increasing the concentration of greenhouse gases in Earth's atmosphere
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