AST 105 Review for Exam #2 Fall 2003
MULTIPLE
CHOICE. Choose the one alternative that
best completes the statement or answers the question.
1) The
allowed shapes for orbits under the force of gravity are
A) ellipses only.
B) ellipses and
spirals.
C) ellipses,
parabolas, and hyperbolas.
D) ellipses,
spirals, and parabolas.
E) spirals,
circles, and squares.
2) Thermal
radiation is defined as
A) radiation
produced by a hot object.
B) radiation in
the infrared part of the spectrum.
C) radiation that
depends only on the emitting object's temperature.
D) radiation in
the form of emission lines from an object.
E) radiation that
is felt as heat.
3) 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?
A) The galaxy is
moving away from you.
B) The galaxy is
moving toward you.
C) The galaxy has
very weak gravity.
D) The galaxy is
made purely of hydrogen.
E) The composition
of the galaxy is changing.
4) Newton's second law of motion tells us that
the net force applied to an object equals its
A) mass times
energy.
B) momentum times
velocity.
C) mass times
velocity.
D) energy times
acceleration.
E) mass times
acceleration.
5) Which of the following could not be
determined by an observation that uses only
spectroscopy?
A) the chemical
composition of a distant star
B) the speed at
which a distant galaxy is moving away from us
C) the surface
temperature of a distant star
D) the rotation
rate of a distant star
E) the size of a
distant galaxy
6) Without telescopes or other aid, we can look
up and see the Moon in the night sky because it
A) emits visible
light.
B) emits thermal
radiation.
C) reflects
infrared light.
D) reflects
visible light.
E) glows through
radioactive decay.
7) When an electron in an atom goes from a higher
energy state to a lower energy state, the
atom
A) emits a photon
of a specific frequency.
B) absorbs a
photon of a specific frequency.
C) absorbs several
photons of a specific frequency.
D) can emit a
photon of any frequency.
E) can absorb a
photon of any frequency.
8) You are standing on a scale in an elevator.
Suddenly you notice your weight decreases. What do you conclude?
A) The elevator is
accelerating upwards.
B) The elevator is
moving at a constant velocity upwards.
C) The elevator is
accelerating downwards.
D) The elevator is
moving at a constant velocity downwards.
E) Your diet is
working.
9) Which of the following is an example in which
you are traveling at constant speed but not at constant velocity?
A) rolling freely
down a hill in a cart, traveling in a straight line
B) driving
backward at exactly 50 km/hr
C) driving around
in a circle at exactly 100 km/hr
D) jumping up and
down, with a period of exactly 60 hops per minute
E) none of the
above
10) Suppose you see two stars: a blue star and a
red star. Which of the following can you conclude about the two stars? Assume
that no Doppler shifts are involved. (Hint: Think about the laws of
thermal radiation.)
A) The red star is
more massive than the blue star.
B) The blue star
is more massive than the red star.
C) The blue star
is farther away than the red star.
D) The blue star
has a hotter surface temperature than the red star.
E) The red star
has a hotter surface temperature than the blue star.
11) What quantities does angular momentum
depend upon?
A) mass and
velocity
B) mass, velocity,
and radius
C) force and
radius
D) force,
velocity, and radius
E) momentum and
angular velocity
12) How are wavelength, frequency, and energy
related for photons of light?
A) Longer
wavelength means lower frequency and lower energy.
B) Longer
wavelength means higher frequency and lower energy.
C) Longer
wavelength means higher frequency and higher energy.
D) Longer
wavelength means lower frequency and higher energy.
E) There is no
simple relationship because different photons travel at different speeds.
13) When an atom absorbs a photon containing
energy, any of the following can happen
except which?
A) The atom
becomes excited.
B) The atom is
ionized.
C) An electron
moves from an upper energy level to a lower one.
D) An electron
moves from a lower energy level to an upper one.
14) From shortest to longest wavelength, which of
the following correctly orders the different categories of electromagnetic
radiation?
A) infrared,
visible light, ultraviolet, X rays, gamma rays, radio
B) radio,
infrared, visible light, ultraviolet, X rays, gamma rays
C) visible light,
infrared, X rays, ultraviolet, gamma rays, radio
D) gamma rays, X rays,
ultraviolet, visible light, infrared, radio
E) gamma rays, X
rays, visible light, ultraviolet, infrared, radio
15) When an atom loses an electron, it becomes
A) sublimated.
B) dissociated.
C) ionized.
D) an isotope.
E) a plasma.
16) Suppose an object is moving in a straight line
at 50 mi/hr. According to Newton's first law of motion, the object will
A) continue to
move in the same way forever, no matter what happens.
B) continue to
move in the same way until it is acted upon by a force.
C) eventually slow
down and come to a stop.
D) continue to
move in a straight line forever if it is in space, but fall to the ground if it
is on
Earth.
17) Which of the following statements about X rays
and radio waves is not true?
A) Neither X rays nor
radio waves can penetrate the Earth's atmosphere.
B) X rays have
shorter wavelengths than radio waves.
C) X rays and
radio waves are both forms of light, or electromagnetic radiation.
D) X rays have
higher frequency than radio waves.
E) X rays have
higher energy than radio waves.
18) The spectra of most galaxies show redshifts.
This means that their spectral lines
A) always are in
the red part of the visible spectrum.
B) have
wavelengths that are longer than normal.
C) have wavelengths
that are shorter than normal.
D) have a higher
intensity in the red part of the spectrum.
E) have normal
wavelengths, but absorption of light makes them appear red.
19) How can an electron in an atom lose energy to
go from a higher energy level to a lower energy level?
A) It loses
kinetic energy.
B) It releases a
photon equal in energy to its own energy drop.
C) It absorbs a
photon equal in energy to its own energy drop.
D) It loses
gravitational potential energy.
E) It exchanges
gravitational potential energy for kinetic energy.
20) If your mass is 60 kg on Earth, what would
your mass be on the Moon?
A) 10 lb B) 10 kg C) 50 kg D) 60 kg E) 60 lb
21) Momentum
is defined as
A) mass times
speed.
B) mass times
velocity.
C) force times
velocity.
D) mass times
acceleration.
E) force times
acceleration.
22) According to the universal law of
gravitation, the force due to gravity is
A) directly
proportional to the square of the distance between objects.
B) inversely
proportional to the square of the distance between objects.
C) directly
proportional to the distance between objects.
D) inversely
proportional to the distance between objects.
E) not dependent
on the distance between objects.
23) Grass
(that is healthy) looks green because
A) it emits green
light and absorbs other colors.
B) it absorbs
green light and emits other colors.
C) it transmits
green light and emits other colors.
D) it reflects
green light and absorbs other colors.
24) From laboratory measurements, we know that a
particular spectral line formed by hydrogen appears at a wavelength of 486.1
nanometers (nm). The spectrum of a particular star shows the same hydrogen line
appearing at a wavelength of 485.9 nm. What can we conclude?
A) The star is
moving toward us.
B) The star is
moving away from us.
C) The star is
getting hotter.
D) The star is
getting colder.
E) The
"star" actually is a planet.
25) The frequency of a wave is
A) the number of
peaks passing by any point each second.
B) measured in
cycles per second.
C) measured in
hertz (Hz).
D) equal to the
speed of the wave divided by the wavelength of the wave.
E) all of the
above.
1) Answer: C
2) Answer: C
3) Answer: A
4) Answer: E
5) Answer: E
6) Answer: D
7) Answer: A
8) Answer: C
9) Answer: C
10) Answer: D
11) Answer: B
12) Answer: A
13) Answer: C
14) Answer: D
15) Answer: C
16) Answer: B
17) Answer: A
18) Answer: B
19) Answer: B
20) Answer: D
21) Answer: B
22) Answer: B
23) Answer: D
24) Answer: A
25) Answer: E