Reference no: EM133296087
1. According to Hubble's Law, galaxies that are twice as far from the Earth are on average moving twice as fast away from the Earth. The equation that governs this motion is given by v = Hd, where v is the average speed of all the galaxies at a given distance, d is the distance from the Earth and H is a constant. As a consequence of this relationship astronomers have been able to estimate the
critical density of the universe.
number of galaxies in the universe.
age of the universe.
mass of the universe.
Earth's location in the universe.
2. Which sequence correctly describes the evolution of the Sun?
main sequence, red giant, white dwarf, protostar
main sequence, protostar, white dwarf, red giant
protostar, main sequence, red giant, white dwarf
white dwarf, red giant, main sequence, protostar
3. A line in a star's spectrum lies at 400.0 nm. In the laboratory, that same line lies at 400.2 nm. How fast is the star moving along the line of sight?
+150,000 m/s
-15,000 m/s
-150,000 m/s
+15,000 m/s
4. In what part of the H-R diagram do white dwarfs lie?
on the main sequence
lower center
upper right
upper left
5. A star that is cool and very luminous must have
a very small radius.
a very great distance.
a very small mass.
a very large radius.