Transcript File

Practice Test
Chapter 15
The Sun, planets and their moons, and
a large collection of smaller objects
such as asteroids, comets, and
meteors are, together, called the:
A.
B.
C.
D.
universe.
galaxy.
solar system.
nebulae.
A unit used to measure long
distances, equivalent to the
distance from the Sun to Earth,
is known as the:
a. light year.
b. cosmic scale.
c. astronomical unit.
d. sidereal year.
Terrestrial planets include all of
the following EXCEPT:
a. Mercury.
b. Venus.
c. Earth.
d. Jupiter.
The gas planets include all of
the following EXCEPT:
a. Jupiter.
b. Venus.
c. Saturn.
d. Uranus.
All of these objects in the
night sky are seen because
they reflect light EXCEPT:
a. Earth’s moon.
b. Venus.
c. stars.
d. Mercury.
A “shooting star” is seen
when this object enters
Earth’s atmosphere and is
vaporized:
a. a comet.
b. a planetary satellite.
c. an asteroid.
d. a meteor.
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Of the planets shown,
the one which
requires the longest
time for one
revolution of the sun
is:
a. Mars.
b. Venus.
c. Earth.
d. Mercury.
The force of gravity between two
objects will be greatest if their
masses are:
a. small and they far apart.
b. large and they are close
together.
c. large and they are far apart.
d. small and they are close
together.
The asteroid belt is located
between the planets:
a. Mercury and Venus.
b. Earth and Mars.
c. Mars and Jupiter.
d. Saturn and Uranus.
The diagram which
best represents the
comparison
between the
diameters of the
moon and Earth is:
 A. 1
 b. 2
 c. 3
 d. 4
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It would be difficult to live
on the moon because it
lacks all of the following
EXCEPT:
a. air.
b. water.
c. gravity.
d. normal temperatures.
Practice Test
Chapter 16
The phrase “a giant, hot ball
of gases” best describes a:
a. planet.
b. moon.
c. star.
d. meteorite.
The source of the Sun’s heat
and light energy is:
a. combustion of helium gas.
b. fusion of hydrogen nuclei.
c. gravitational pressure.
d. burning of fossil fuels.
The main characteristics used
to classify stars include all of
the following EXCEPT:
a. shape.
b. brightness.
c. color.
d. temperature.
The color of the hottest
stars is:
a. red.
b. orange.
c. yellow.
d. blue.
By size, the star known as
our Sun is classified as:
a. supergiant.
b. giant.
c. average.
d. dwarf.
Scientists measure distances
beyond our solar system
(such as the distance
between two stars) using
these units:
a. meters
b. kilometers
c. astronomical units
d. light years
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According to the H-R
diagram in Figure 161A, the areas labeled
B and E would be
classified as:
a. red and blue
supergiants
b. the main
sequence.
c. white dwarfs.
d. red giants.
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According to the H-R
diagram in Figure 161A, the areas labeled
C and D would be
classified as:
a. red and blue
supergiants.
b. white dwarfs.
c. the main
sequence.
d. red giants.
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As a group, stars
known as main
sequence stars on an
H-R diagram are best
described as being:
a. hotter.
b. larger.
c. stable.
d. brighter.
The explosion of a very
large star is known as a:
a. black hole.
b. white dwarf.
c. neutron star.
d. supernova.
A star begins to form when
gravitational forces cause denser
regions of a huge cloud of gas
and dust to collapse. The earliest
stage of a star’s life cycle is called
the:
a. protostar.
b. red giant.
c. white dwarf.
d. supernova.
When the core of a star runs out of
hydrogen:
a. nuclear fusion stops and the star
stops producing light.
b. the core contracts, raising the
temperature so that other fusion
reactions occur.
c. the star is immediately crushed
into a black hole.
d. the star becomes a white dwarf
and then a red giant.
Chapter 16
Math Problems
Sirius is about 8.8 light years
from Earth. If one light year
equals 9.46 ´ 1012 kilometers,
how far is Sirius from Earth,
measured in kilometers?
a. 8.3 ´ 1013 kilometers
b. 1.1 ´ 1013 kilometers
c. 8.3 ´ 1011 kilometers
d. 1.1 ´ 1011 kilometers
The distance from Earth to the star
Proxima Centauri is 4.01 ´ 1013
kilometers. What is this distance in
light years? One light year is equal
to 9.46 ´ 1012 kilometers.
a. 0.424 light years
b. 4.24 light years
c. 42.4 light years
d. 424 light years
If you were traveling at 30 kilometers
per second, how long would it take to
reach Proxima Centauri, the nearest
star to Earth other than our Sun?
Proxima Centauri is 4.01 ´ 1013
kilometers from Earth. Hint: there are
31,557,600 seconds in one year.
a. Approximately 134 years
b. Approximately 4,240 years
c. Approximately 42,400 years
d. Approximately 1,340,000,000,000
years