ISP 205 Visions of the Universe Exam 1 Answers

1) Which of the following has your "cosmic address" in the correct order?
A) you, Earth, solar system, Local Group, Local Supercluster, Milky Way Galaxy
B) you, Earth, solar system, Milky Way Galaxy, Local Group, Local Supercluster
C) you, Earth, solar system, Local Group, Milky Way Galaxy, Local Supercluster

B) you, Earth, solar system, Milky Way Galaxy, Local group, Local Supercluster

2) What is the ecliptic plane?
A) the plane of Earth's orbit around the Sun
B) the plane of Earth's equator
C) the plane of the Sun's equator
D) the plane of the Milky Way Galaxy

A) the plane of Earth's orbit around the Sun

3) Suppose we imagine the Sun to be about the size of a grapefruit. How big an area would the orbits of the eight planets of the solar system cover?
A) the size of a small room
B) the size of a building
C) the size of a typical college campus
D) the size of a small city
E) the size of a western state (e.g., Colorado)

C) the size of a typical college campus

4) On the cosmic calendar, where every month is about 1.2 billion years long, and where the Big Bang happened on January 1, when did the Sun and Earth form?
A) January
B) December
C) September
D) February

C) September

5) The universe is defined as
A) all the stars and galaxies that we can see with telescopes.
B) all the objects we can see and the space between them.
C) all material, space, and energy that exist: everything.
D) the entire Milky Way Galaxy.

C) all material, space, and energy that exist: everything

6) When both are viewed from a distance away from Earth, would a person standing on the South Pole appear to be oriented upside down compared with a person standing on the North Pole?
A) No, they would both be standing in the same orientation because "up" is always in the same
direction on Earth.
B) No, that would imply the South Pole person would fall off the globe.
C) Yes, but they each would believe they were standing upright.
D) Yes, but they would each have the North Star, Polaris, above their head.

C) Yes, but they each would believe they were standing upright.

7) A person located on the equator is orbiting the center of the Earth to the East at 1670 km/s. Relative to the center of the Earth, a person on the North Pole is
A) moving at the same velocity to the East, since they are both on the same planet in space.
B) moving toward the South at the same velocity.
C) not moving at all.
D) stationary, except spinning in-place once per day.

D) stationary, except spinning in-place once per day.

8) Which of the following represents a case in which you are not accelerating?
A) driving in a straight line at 60 miles per hour
B) going from 0 to 60 miles per hour in 10 seconds
C) slamming on the brakes to come to a stop at a stop sign
D) driving 60 miles per hour around a curve

A) driving in a straight line at 60 miles per hour

9) Which statement about motion in the universe is not true?
A) The mysterious dark matter is the fastest-moving material in the universe.
B) Some stars in the Milky Way Galaxy are moving toward us and others are moving away from us.
C) Except for a few nearby galaxies, all other galaxies are moving away from us.
D) Your speed of rotation around Earth's axis is faster if you live near the equator than if you live near
the North Pole.

A) The mysterious dark matter is the fastest-moving material in the universe.

10) The number of stars in the Milky Way Galaxy is approximately ________.
A) a few million
B) a few hundred million
C) a few billion
D) a few hundred billion

D) a few hundred billion

11) Where did the elements hydrogen and most helium form?
A) Stars
B) Planets
C) Comets
D) Big Bang

D) Big Bang

12) Which of the following statements about the celestial equator is true at all latitudes?
A) It lies along the band of light we call the Milky Way.
B) It represents an extension of Earth's equator onto the celestial sphere.
C) It cuts the dome of your local sky exactly in half.
D) It extends from your horizon due east, through your zenith, to your horizon due west.
E) It extends from your horizon due north, through your zenith, to your horizon due south.

B) It represents an extension of Earth's equator onto the celestial sphere.

13) The number of official constellations is
A) 56.
B) 88.
C) 123.
D) 205.

B) 88

14) How many arcseconds are in one degree?
A) 60
B) 360
C) 3,600
D) 100
E) 10,000

C) 3,600

15) What do astronomers mean by a constellation?
A) A constellation is a region in the sky as seen from Earth.
B) A constellation is a group of stars related through an ancient story.
C) A constellation is any random grouping of stars in the sky.
D) A constellation is a group of stars that are all located in about the same place in space.

A) A constellation is a region in the sky as seen from Earth.

16) Consider three circles that may be imaginatively "drawn" across the night sky (note that we see
only parts of each circle at any time): the Milky Way; the ecliptic; and the celestial equator. Which
statement about these circles is true?
A) The celestial equator is unique, since it traces the path of an object, namely, the Sun.
B) The ecliptic circle is unique as it traces a broad band of stars.
C) The Milky Way and the ecliptic are the only two circles that are tilted relative to each other.
D) Only the ecliptic circle passes through all the zodiacal constellations.
E) All three circles cross at the same two points: the equinoxes.

D) Only the ecliptic circle passes through all the zodiacal constellations.

17) The ecliptic crosses the celestial equator on the celestial sphere at points called
A) the equinoxes.
B) the solstices.
C) the nodes.
D) aphelion and perihelion.

A) the equinoxes.

18) Which of the following statements does not use the term angular size or angular distance
correctly?
A) The angular distance between those two houses in the distance is 30 degrees.
B) The angular distance between those two bright stars in the sky is about 2 meters.
C) The angular size of the Sun is about the same as that of the Moon.
D) You can use your outstretched hand against the sky to estimate angular sizes and angular distances.

B) The angular distance between those two bright stars in the sky is about 2 meters.

19) The stars stay in "fixed" positions on the celestial sphere because
A) the stars on the sphere are all chosen to be approximately the same distance from Earth.
B) while they actually move through space, they are too far away for their motion to be seen.
C) the sphere to which they are attached moves with them through space.
D) they are all expanding away, so they have no transverse (sideways) motions.

B) while they actually move through space, they are too far away for their motion to be seen.

20) Which of the following best describes why we have seasons on Earth?
A) The tilt of Earth's axis causes different portions of the Earth to receive more direct sunlight and
more hours of sunlight at different times of year.
B) Earth's elliptical orbit means we are closer to the Sun and therefore receive more intense sunlight at
some times of year than at others.
C) The tilt of Earth's axis causes the northern hemisphere to be closer to the Sun than the southern
hemisphere in summer, and vice versa in winter.
D) The varying speed of Earth in its orbit around the Sun gives us summer when we are moving fastest
and winter when we are moving slowest.

A) The tilt of Earth's axis causes different portions of the Earth to receive more direct sunlight and more hours of sunlight at different times of year.

21) How does Earth's varying distance from the Sun affect our seasons?
A) It doesn't. Earth's orbital distance plays no significant role in the seasons.
B) It makes summer warmer in the Northern Hemisphere than in the Southern Hemisphere.
C) It is responsible for the fact that the seasons are opposite in the Northern and Southern hemispheres.
D) It causes the seasons to be more extreme than they would be if the Earth's distance from the Sun
were always the same.

A) It doesn't. Earth's orbital distance plays no significant role in the seasons.

22) Which of the following conditions must exist for a solar eclipse to occur?
A) The only condition is that the phase of the Moon must be new.
B) The only condition is that the phase of the Moon must be full.
C) Moon phase is new, and the Moon is passing through the Earth's orbital plane.
D) Moon phase is full, and the Moon is passing through the Earth's orbital plane.

C) Moon phase is new, and the Moon is passing through the Earth's orbital plane.

23) You are standing on Earth's equator. In which direction is Polaris, the North star?
A) The answer depends on what time of day (or night) it is.
B) The answer depends on whether it is winter or summer.
C) It is on the northern horizon.
D) It is directly overhead.

C) It is on the northern horizon.

24) Today the Sun is in the middle of the constellation Virgo. Therefore, tomorrow the Sun will be in
the constellation
A) Libra.
B) Virgo.
C) Leo.
D) Sagittarius.

B) Virgo.

25) If Earth's rotation axis was tilted by 45 degrees instead of 23.5 degrees, what are some of the
implications, and why?
A) The seasons would be more extreme, because the Sun's rays would be more direct in summer, and
less direct in winter.
B) The seasons would be more extreme, because the surface of the Earth would be closer to the Sun in
the summer, and farther from the Sun in the winter.
C) The seasons would be less extreme, because the Sun's rays would be less direct in summer, and
more direct in winter.
D) The seasons would be less extreme, because the surface of the Earth would be farther from the Sun
in the summer, and closer to the Sun in the winter.

A) The seasons would be more extreme, because the Sun's rays would be more direct in summer, and less direct in winter.

26) The acceleration of gravity on Earth is approximately 10 m/s2 (more precisely, 9.8 m/s2). If you
drop a rock from a tall building, about how fast will it be falling after 3 seconds?
A) 30 m/s
B) 10 m/s
C) 30 m/s2
D) 10 m/s2
E) 20 m/s

A) 30 m/s

27) You are standing on a scale in an elevator. You notice your weight suddenly decreases and remains
decreased. 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.

C) The elevator is accelerating downwards.

28) Suppose an object is moving in a straight line at 70 km/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.

B) continue to move in the same way until it is acted upon by a force.

29) How does a rocket launched into space take off?
A) Its rocket engines push against the launch pad, propelling the rocket upwards.
B) By converting mass-energy to potential energy.
C) By achieving lift from its wings in the same way that airplanes do.
D) Hot gas shoots out from the rocket and, through the conservation of momentum, the rocket moves in
the opposite direction.
E) The hot rocket exhaust expands the air beneath the shuttle, propelling it forward.

D) Hot gas shoots out from the rocket and, through the conservation of momentum, the rocket moves in the opposite direction.

30) 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.

B) inversely proportional to the square of the distance between objects.

31) The fact that Voyager 10 continues to speed out of the solar system even though its rockets have no
fuel, is an example of
A) Newton's first law of motion.
B) Newton's second law of motion.
C) Newton's third law of motion.
D) the universal law of gravitation.
E) none of the above

A) Newton's first law of motion.

32) 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

B) mass, velocity, and radius

33) Newton's version of Kepler's third law states: p^2 =
4pi^2/G(M1 + M2)× a^3
In this equation, what does G represent?
A) the orbital period
B) the average distance between the two objects
C) the masses of the two objects
D) the universal gravitational constant

D) the universal gravitational constant

34) When is a comet's orbital angular momentum at its maximum?
A) when the comet is close to the Sun
B) when the comet is far away from the Sun
C) Its angular momentum does not change.

C) Its angular momentum does not change.

35) If an object's velocity is doubled, its momentum is
A) halved.
B) unchanged.
C) doubled.
D) quadrupled.
E) dependent on its acceleration.

C) doubled.

36) If a spinning star suddenly gets bigger in diameter, what happens to its rotation rate?
A) It increases.
B) It is unaffected.
C) It decreases.

C) It decreases.

37) Absolute zero is ________.
A) 0 Kelvin
B) 0° Celsius
C) 0° Fahrenheit
D) 100° Celsius

A) 0 Kelvin

38) What is the difference between a bound orbit and an unbound orbit around the Sun?
A) An object on a bound orbit follows the same path around the Sun over and over, while an object on
an unbound orbit approaches the Sun just once and then never returns.
B) A bound orbit is an orbit allowed by the universal law of gravitation, and an unbound orbit is not.
C) An object on a bound orbit has a gravitational attraction to the Sun, while an object on an unbound
orbit does not.
D) A bound orbit is circular, while an unbound orbit is elliptical.

A) An object on a bound orbit follows the same path around the Sun over and over, while an object on an unbound orbit approaches the Sun just once and then never returns.

39) Consider the gravitational force between the Sun and Earth. Which of the following statements
describes the situation the best?
A) The gravitational force experienced by the Sun is equal and opposite to the gravitational force
experienced by the Earth.
B) The acceleration experienced by the Sun due to the Earth is equal and opposite to the acceleration
experienced by the Earth due to the Sun.
C) Both of these statements are true.

A) The gravitational force experienced by the Sun is equal and opposite to the gravitational force experienced by the Earth.

40) Suppose that the Sun shrank in size but that its mass remained the same. What would happen to the
orbit of the Earth?
A) Earth's orbit would be unaffected.
B) The size of Earth's orbit would shrink, and it would take less than one year to orbit the Sun.
C) Earth's orbit would expand, and it would take more than one year to orbit the Sun.
D) Earth would change from a bound orbit to an unbound orbit and fly off into interstellar space.

A) Earth's orbit would be unaffected.