Many disk galaxies, such as Andromeda and the Milky Way, are thought to have extended halos of dark matter because the disk circular orbital speed is observed to ____________ increasing distances from the disk center
a. stay constant with
b. decrease with
c. be totally absent at
a
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A molecule has
A) mass. B) structure. C) energy. D) all of the above E) none of the above
Which of the following is the most convincing observation that suggests that like Europa, Ganymede may also have a subsurface ocean?
A) the detection of salts on the surface that may have been brought up from below the crust B) the presence of young grooved terrain that may be the result of cryovolcanism C) the fact that it is the largest moon in the solar system and, hence, should have plenty of internal heat to maintain liquid water beneath its surface D) in addition to its internal magnetic field, Ganymede has a magnetic field induced by Jupiter which is consistent with a salty ocean beneath its crust
Which of the following quantities expressed in derived units includes the unit of length?
a. Area b. Volume c. Speed d. Density e. All of these
The electrical power dissipated by a resistance R is
a. inversely proportional to I. b. directly proportional to I2. c. directly proportional to I. d. none of these.