ASTRO 207 Midterm 2 Exam - Questions with 100% Correct Answers

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ASTRO 207 Midterm 2 Exam - Questions with 100% Correct Answers How much electrical charge does an atom with 6 protons, 6 neutrons, and 5 electrons have? A) a positive charge of +1 B) a total charge ... of +17 C) a positive charge of +7 D) a negative charge of -5 E) none of the above Suppose the angular separation of two stars is smaller than the angular resolution of your eyes. How will the stars appear to your eyes? A) you will not be able to see these two stars at all B) you will see two distinct stars C) the two stars will appear to be touching, looking rather like a small dumbbell D) the two stars will look like a single point of light E) you will see only the larger of the two stars, not the smaller one In which of the following cases would you feel weightless? A) while walking on the Moon B) while falling from a roof C) while falling from an airplane with your parachute open D) while traveling through space in an accelerating rocket E) none of the above Which of the following is not an advantage of spacecraft flybys over ground-based telescope observations? A) spacecraft can measure local magnetic fields B) spacecraft can monitor changed in a planet's atmosphere over long times C) spacecraft can make highly detailed imaged of the planet and its moons D) spacecraft can sample the gravitational field of a planet E) spacecraft can view "backlit" views of planetary rings Which of the following observations indicates that conditions on Mars may have been suitable for life in the past? A) There are very large extinct volcanoes on Mars B) Mas has polar caps made of "dry ice" C) Mars has two small moons D) there is a very deep and long canyon that extends across Mars E) there is liquid water as well as a significant number of dried-up riverbeds on Mars When light reflects off an object, what is the relation between the angle of incidence and the angle of reflection? A) angle of incidence + angle of reflection= 180 degrees B) angle of incidence + angle of reflection= 90 degrees C) angle of incidence= angle of reflection D) angle of incidence- angle of reflection= 90 degrees E) it depends on the material that light reflects off What do astronomers mean by light pollution? A) light pollution refers to light used for human activities that brightens the sky and hinders astronomical observations B) light pollution refers to harmful gases emitted by common street lights C) light pollution refers to the lights that must be used inside major observatories and that make it difficult for astronomers' eyes to adapt to darkness D) light pollution is another name for sunlight, which makes it impossible to see stars in the daytime E) light pollution refers to pollution caused by light industry as opposed to heavy industry Which of the following statements correctly describes the law of conservation of energy? A) an object always has the same amount of energy B) the total quantity of energy in the universe never changes C) energy can change between many different forms, such as potential, kinetic, and thermal, but it is ultimately destroyed D) the fact that you can fuse hydrogen into helium to produce energy means that helium can be turned into hydrogen to produce energy E) it is not really possible for an object to gain or lose potential energy, because energy cannot be destroyed Which of the following statements about electrical charge is true? A) a positive charge and a negative charge will attract each other B) two positive charges will attract each other C) two negative charges will attract each other D) a positive charge and a negative charge will repel each other Which planet, other than Earth, has visible what ice on it? A) Mars B) Venus C) the Moon D) Jupiter E) Mercury Grass appears green because: A) it reflects green light and absorbs other colours B) it emits green light and absorbs other colours C) it transmits green light and emits other colours D) it absorbs green light and emits other colours According to the universal law of gravitation, if you triple the distance between two objects, the gravitational force between them with: A) decrease by a factor of 6 B) increase by a factor of 9 C) decrease by a factor of 3 D) increase by a factor of 3 E) decrease by a factor of 9 If you drop a rock from a great height, about how fast will it be falling after 5 seconds, neglecting air resistance? A) 10 m/s B) it depends on how heavy it is C) it depends on what shape it is D) 15 m/s E) 50 m/s A gas heated to millions of degrees would emit: A) mostly X-rays B) no light, because it is too hot C) mostly ultraviolet light D) mostly radio waves E) an equal amount of all wavelengths of light Which planet has a ring system? A) Jupiter B) Neptune C) Uranus D) Saturn E) all of the above Which of the following is farthest from the Sun? A) a comet in the Kuiper belt B) Neptune C) Pluto D) an asteroid in the asteroid belt E) a comet in the Oort cloud Which of the following could not be measured by an observation that uses only imaging? A) the brightness of a star in our sky B) the rate at which a variable star brightens and dims C) the colour of a planet D) the general shape of an interstellar cloud of gas E) the number of bright stars in a nearby star cluster 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? A) the star is getting hotter B) the star is getting colder C) the "star" actually is a planet D) the star is moving away from us E) the star is moving toward us In what part of the electromagnetic spectrum do the biggest telescopes on Earth operate? A) infrared B) ultraviolet C) X-ray D) radio E) visibility What is the primary reason why a Pluto flyby mission would be cheaper than a Pluto orbiter? A) the fuel needed for an orbit to slow down when it reaches Pluto is very expensive in and of itself B) the fuel needed for an orbiter to slow down when it reaches Pluto adds a lot of weight to the spacecraft C) the flyby is easier to design than the orbiter D) the flyby can use less expensive cameras than the orbiter E) the question is incorrect; in general, orbiters are cheaper than flybys What causes stars to twinkle? A) the inability of the human eye to see faint objects B) variable absorption by interstellar gas along the line of sight to the star C) variations in the absorption of the atmosphere D) it is intrinsic to the stars- their brightness varies as they expand and contract E) bending of light rays by turbulent layers in the atmosphere Which of the following is not a good reason to place observatories on remote mountain tops? A) to reduce light distortion B) to reduce light absorption C) to be able to observe at infrared wavelengths D) to be able to observe at radio wavelengths E) to reduce light pollution 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? A) we can look at Doppler shifts at spectral lines to determine the star's speed toward or away from us B) we can identify chemical elements present in the star by recognizing patterns of spectral lines that correspond to particular chemicals C) the peak of the star's thermal emission tell us it's temperature: Hotter stars peak at shorter (bluer) wavelengths D) the total amount of light in the spectrum tells us the star's radius Momentum is defined as: A) mass times speed B) force times acceleration C) mass times acceleration D) force times velocity E) mass times velocity Which of the following statements about electrons is not true? A) electrons can jump between energy levels in an atom only if they receive or give up an amount of energy equal to the difference in energy between the energy levels B) an electron has a negative electrical charge C) electrons orbit the nucleus rather like planets orbiting the Sun [Show More]

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