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2010-11-11 15:33:09
Dowdy astron test3

Practice test
Show Answers:

  1. If two objects are the same size but one object is 3 times hotter than the other object, the hotter object emits
    81 times more energy.
  2. From shortest to longest wavelength, which of the following correctly
    orders the different categories of electromagnetic radiation?
    gamma rays, X rays, ultraviolet, visible light, infrared, radio
  3. Which of the following statements about electrical charge is true?
    A positive charge and a negative charge will attract each other.
  4. Which of the following is a principal advantage of CCDs over photographic film?
    CCDs capture a much higher percentage of the incoming photons than does film.
  5. Which of the following wavelength regions cannot be studied with telescopes on the ground?
    both B and C
  6. The amount of gravitational potential energy released as an object falls depends on
    its mass and the distance it falls.
  7. The fact that the Voyager spacecraft continue to speed out of the solar system, even though its rockets have no fuel, is an example of
    Newton's first law of motion.
  8. What are the main constituents of the jovian planets?
    hydrogen and helium
  9. According to the universal law of gravitation, if you triple the distance between two objects, then the gravitational force between them will
    decrease by a factor of 9.
  10. You observe a distant galaxy. You find that a spectral line normally
    found in the visible part of the spectrum is shifted toward the
    infrared. What do you conclude?
    The galaxy is moving away from you.
  11. Which planet has the highest average surface temperature, and why?
    Venus, because of its dense carbon dioxide atmosphere
  12. When white light passes through a cool cloud of gas, we see
    an absorption line spectrum.
  13. What is the primary reason why a Pluto flyby mission would be cheaper than a Pluto orbiter?
    The fuel needed for an orbiter to slow down when it reaches Pluto adds a lot of weight to the spacecraft.
  14. Currently, the largest optical telescope mirrors have a diameter of
    10 m.
  15. What causes stars to twinkle?
    bending of light rays by turbulent layers in the atmosphere
  16. In which of the following cases would you feel weightless?
    while falling from a roof
  17. Which of the following is not an advantage of the Hubble Space Telescope over ground-based telescopes?
    It is closer to the stars.
  18. Which of the following is an example in which you are traveling at constant speed but not at constant velocity?
    driving around in a circle at exactly 100 km/hr
  19. The ultimate source of energy that powers the Sun is
    mass energy of hydrogen fusing into helium.
  20. Grass (that is healthy) looks green because
    it reflects green light and absorbs other colors.
  21. The tides on Earth are an example of
    the universal law of gravitation.
  22. What is the acceleration of gravity of Earth?
    9.8 m/s2 downward
  23. We can see each other in the classroom right now because we
    reflect visible light.
  24. If a material is highly opaque, then it
    absorbs most light.
  25. In what part of the electromagnetic spectrum do the biggest telescopes on Earth operate?
  26. The movement of a pool ball, after being struck by a cue, is an example of
    Newton's second law of motion.
  27. Newton's second law of motion tells us that the net force applied to an object equals its
    mass times acceleration.
  28. The planet closest in size to Earth is
  29. Where are most of the known asteroids found?
    between the orbits of Mars and Jupiter
  30. The frequency of a wave is
    all of the above
  31. What do astronomers mean by light pollution?
    Light pollution refers to light used for human activities that brightens the sky and hinders astronomical observations.
  32. 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
  33. If an object's velocity is doubled, its momentum is
  34. Which planet has a ring system?
    all of the above
  35. How does the Sun's mass compare with that of the planets?
    It is a thousand times more massive than all the planets combined.