Astronomy HW 4 questions and answers

Which of the following defines density? a) weight of an object b) mass divided by volume c) size divided by weight d) mass times weight b) mass divided by volume Which of the following objects would never be encountered on the moon? a) Meteoroids b) Meteors c) Meteorites d) all of the above b) Meteors 00:27 01:13 The nucleus, or main solid body, of a comet has a typical size of a) A few meters b) A few kilometers c) A few hundred kilometers d) A few centimeters b) A few kilometers The orbits of most asteroids: a) Lie beyond the orbit of Mars. b) Cross the orbit of Mars. c) Cross the orbit of Earth. d) Bring them near the Sun; these asteroids are called Sungrazers. a) Lie beyond the orbit of Mars. Comets are thought to reside mainly in: a) The inner solar system. b) Distant galaxies. c) The Oort Cloud and Kuiper Belt. d) Solar nebulae. c) The Oort Cloud and Kuiper Belt. What causes the bright flash of light as a meteor plunges through the atmosphere? a) The meteor glows white hot b) Lightning sparked by the meteor's passage c) Air molecules ionized by the friction of the meteor's passage d) All of the above c) Air molecules ionized by the friction of the meteor's passage Why doesn't Earth itself provide many clues to the origin of the solar system? a) Each planet was formed by an entirely different process. b) The planets formed at different times. c) Most of the planets formed in a similar process, but Earth, with its oceans and life, formed differently. d) Information about our planet's early stages eroded away long ago. d) Information about our planet's early stages eroded long ago. In light of modern solar system theory, why do the orbits of the planets all lie in nearly the same plane? a) The Sun's gravity forced them into these orbits. b) The angular momentum of the solar system was kept to a minimum this way. c) The early solar nebula flattened into a disk. d) This happened purely by chance. c) The early solar nebula flattened into a disk. What happens when a solar nebula contracts? a) It flattens out. b) It spins faster. c) It heats up. d) all of the above d) all of the above How did Mercury's location in the solar system affect its composition? a) Mercury is rich in metals because only metallic grains could survive the high temperatures so near the Sun. b) Mercury is poor in metals because metallic grains could not survive the high temperatures so near the Sun. c) The nearby Sun caused ice in Mercury's interior to melt into liquid water. d) Because Mercury is so near the Sun, its composition is similar to the Sun; mostly hydrogen and helium. a) Mercury is rich in metals because only metallic grains could survive the high temperatures so near the Sun. Which of the following is NOT a terrestrial planet? a) Mars b) Earth c) Jupiter d) Venus c) Jupiter Which of the following characteristics do all four terrestrial planets have in common? a) they all have solid surfaces with signs of geological activity on them b) they all have liquid water on their surfaces c) they all rotate in 24 hours or less d) they all have thick atmospheres a) they all have solid surfaces with signs of geological activity