Exam 1 | PHYS1350

The solar system contains about 100 billion stars.

False

There are about 200 billion stars in our solar system.

False

Earth is always precisely 1 AU from the Sun.

False

Scientific theories can never be proved true beyond all doubt.

True

Science can say nothing about the validity of nonscientific practices that do not make testable predictions.

True

Kepler figured out his laws of planetary motion using Newton’s laws of motion.

False

There is no gravity in space.

False

No galaxies existed before the Big Bang.

True

A solar eclipse occurs only when the Moon is new.

True

Tidal friction caused by Earth’s stretching from the Moon’s gravity is gradually slowing down the rotation of Earth.

True

At midnight it is sometimes possible to observe the crescent moon on the meridian.

False

You are currently emitting electromagnetic waves.

True

Seen from Earth, the Moon and the Sun are approximately the same angular size.

True

When an astronaut goes on a space walk outside the Space Station, she will quickly float away from the station unless she has a tether holding her to the station or constantly fires her thrusters on her space suit.

False

Grass is green because it absorbs green light, reflecting all other colors.

False

X-rays, because they have more energy, travel through space faster than visible light.

False

The seasons on Earth are caused by the elliptical shape of its orbit around the Sun.

False

Columbus was the first person to discover that Earth is round.

False

In a scale model of the solar system, where the Sun is the size of a grapefruit, it would take a few minutes to walk from the Sun to Pluto.

True

The fact that all galaxies outside of our local group are moving away from us, with more distant galaxies moving faster (velocity is proportional to distance) means that we must be at the center of the Universe.

False

Although all the known stars rise in the east and set in the west, we might someday discover a star that will rise in the west and set in the east.

False

If Earth’s orbit were a perfect circle, we would not have seasons.

False

Galileo’s experiments showed that in the absence of air resistance, heavy objects fall faster than lighter objects.

False

A scientific model must make observational predictions.

True

During retrograde motion, a planet rises in the west and sets in the east instead of rising in the east and setting in the west.

False

Absolute zero is _____.

A) 0 degrees Fahrenheit

B) 100 degrees Celsius

C) 0 degrees Celsius

D) 0 Kelvin

0 Kelvin

How long does it take Earth to complete one orbit around the Sun?

A) One year

B) One week

C) One day

D) One month

E) The time it takes Earth to orbit the Sun changes significantly from one orbit to the next.

One year

The principle of Occam’s Razor states that

A) in explaining natural phenomena, the simplest explanation consistent with the observation is to be preferred.

B) only a model that has survived repeated observational tests deserves to be called a scientific theory.

C) while personal biases may influence individual scientists, the process of science itself can uncover these biases.

D) no scientific theory, no matter how well tested, can ever be proven absolutely true.

E) scientific explanations may invoke supernatural causes if no other causes are found.

in explaining natural phenomena, the simplest explanation consistent with the observation is to be preferred.

What do we mean when we say that the universe is expanding?

A) Average distances between galaxies are increasing with time.

B) Everything in the universe is gradually growing in size.

C) Within galaxies, average distances between star systems are increasing with time.

D) The statement is not meant to be literal; rather, it means that our knowledge of the universe is growing.

Average distances between galaxies are increasing with time.

Suppose we look at two distant galaxies: Galaxy 1 is twice as far away as Galaxy 2. In that case _____.

A) we are seeing Galaxy 1 as it looked at an earlier time in the history of the universe than Galaxy 2.

B) Galaxy 1 must be twice as big as Galaxy 2.

C) Galaxy 2 must be twice as old as Galaxy 1.

D) we are seeing Galaxy 1 as it looked at a later time in the history of the universe than Galaxy 2.

we are seeing Galaxy 1 as it looked at an earlier time in the history of the universe than Galaxy 2.

What is the ecliptic plane?

A) The plane of the Milky Way Galaxy

B) The plane of Earth’s equator

C) The plane of Earth’s orbit around the Sun

D) The plane of the Sun’s equator

The plane of Earth’s orbit around the Sun

According to Kepler’s third law (p² = a³), how does a planet’s mass affect its orbit around the Sun?

A) More massive planets orbit the Sun at higher average speed.

B) More massive planets must have more circular orbits.

C) A planet’s mass has no effect on its orbit around the Sun.

D) A more massive planet must have a large semimajor axis.

A planet’s mass has no effect on its orbit around the Sun.

Consider an atom of gold in which the nucleus contains 79 protons and 118 neutrons. What is its atomic number and atomic mass number?

A) The atomic number is 79, and the atomic mass number is 197.

B) The atomic number is 118, and the atomic mass number is 197.

C) The atomic number is 79, and the atomic mass number is 118.

D) The atomic number is 118, and the atomic mass number is 79.

The atomic number is 79, and the atomic mass number is 197.

The gravitational force of the Sun pulling on the Earth is

A) a little larger than the gravitational force of Earth pulling on the Sun.

B) much smaller than the gravitational force of Earth pulling on the Sun.

C) exactly the same size as the gravitational force of Earth pulling on the Sun.

D) much larger than the gravitational force of Earth pulling on the Sun.

E) a little smaller than the gravitational force of Earth pulling on the Sun.

exactly the same size as the gravitational force of Earth pulling on the Sun.

The great contribution of Nicholas Copernicus was to _____.

A) prove that the Earth is not the center of the universe

B) discover the laws of planetary motion

C) discover the law of gravity

D) create a detailed model of our solar system with the Sun rather than Earth at the center

create a detailed model of our solar system with the Sun rather than Earth at the center

When considering light as made up of individual “pieces”, each characterized by a particular amount of energy, the pieces are called _____.

A) wavicles

B) gamma rays

C) photons

D) electrons

E) frequencies

photons

Only one of the statements below uses the term theory in its correct, scientific sense. Which one?

A) I have a new theory about the cause of earthquakes, and I plan to start testing it soon.

B) I wrote a theory that is 152 pages long.

C) Evolution is only a theory, so there’s no reason to think it really happened.

D) Einstein’s theory of relativity has been tested and verified thousands of times.

Einstein’s theory of relativity has been tested and verified thousands of times.

He discovered that Jupiter has moons.

A) Ptolemy

B) Aristotle

C) Tycho Brahe

D) Galileo

E) Kepler

Galileo

How are wavelength, frequency, and energy related for photons of light?

A) Longer wavelength means lower frequency and lower energy.

B) Longer wavelength means lower frequency and higher energy.

C) Longer wavelength means higher frequency and higher energy.

D) Longer wavelength means higher frequency and lower energy.

E) There is no simple relationship because different photons travel at different speeds.

Longer wavelength means lower frequency and lower energy.

The force of gravity is an inverse square law. This means that, if you double the distance between two large masses, the gravitational force between them

A) also doubles.

B) weakens by a factor of 4.

C) strengthens by a factor of 4.

D) weakens by a factor of 2.

E) is unaffected.

weakens by a factor of 4.

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

Driving in a straight line at 60 miles per hour

Orion is visible on winter evenings but not summer evenings because of

A) the tilt of Earth’s axis.

B) the location of Earth in its orbit.

C) interference from the full moon.

D) the precession of Earth’s axis.

E) baseball on television.

the location of Earth in its orbit.

Which of the following statements about the celestial sphere is not true?

A) The Earth is placed at the center of the celestial sphere.

B) The “celestial sphere” is another name for our universe.

C) When we look in the sky, the stars all appear to be located on the celestial sphere.

D) The Sun, Moon, and planets change their location relative to the stars fixed on the celestial spheres.

E) The celestial sphere does not exist physically.

The “celestial sphere” is another name for our universe.

Which of the following best describes what we mean by the universe?

A) The universe is another name for our Milky Way Galaxy.

B) The sum total of all matter and energy.

C) All the galaxies in all the superclusters.

D) A vast collection of stars that number as many as the grains of sand on all the beaches on Earth.

The sum total of all matter and energy.

On a scale where the Sun is about the size of a grapefruit and the Earth is about 15 meters away, how far away are the nearest stars besides the Sun?

A) About the distance across the state of Delaware

B) 100 meters

C) About the distance across 50 football fields

D) About the distance across the United States

About the distance across the United States

Which of the following scenarios involves energy that we would typically calculate with Einstein’s formula E=mc²?

A) A mass raised to a great height has a lot of gravitational potential energy.

B) A burning piece of wood produces light and heat, therefore giving off radiative and thermal energy.

C) An object accelerated to a great speed has a lot of kinetic energy.

D) A small amount of the hydrogen in of a nuclear bomb becomes energy as fusion converts the hydrogen to helium.

A small amount of the hydrogen in of a nuclear bomb becomes energy as fusion converts the hydrogen to helium.

What is a circumpolar star?

A) a star that always remains above your horizon

B) A star that is visible from the Arctic or Antarctic circles

C) a star that is close to the south celestial pole

D) a star that is close to the north celestial pole

E) a star that makes a daily circle around the celestial sphere

a star that always remains above your horizon

Our solar system consists of _____.

A) the Sun and the planets, and nothing else

B) a few hundred billion stars, bound together by gravity

C) the Sun and all the objects that orbit it

D) the Sun and several nearby stars, as well as the planets and other objects that orbit these stars

the Sun and all the objects that orbit it

Galileo observed all of the following. Which observation offered direct proof of a planet orbiting the Sun?

A) Four moons of Jupiter

B) The Milky Way is composed of many individual stars.

C) Patterns of shadow and sunlight near the dividing line between the light and dark portions of the Moon’s face

D) Phases of Venus

Phases of Venus

We can’t detect stellar parallax with naked-eye observations. Which of the following would make parallax easier to observe?

A) getting away from streetlights

B) increasing the size of Earth’s orbit

C) slowing down Earth’s orbital motion

D)Speeding up the precession of Earth’s axis

E) speeding up Earth’s orbital motion

increasing the size of Earth’s orbit

When someone on Earth observes the Moon in the first-quarter phase, someone on the Moon facing Earth observes Earth in the

A) waning gibbous Earth phase.

B) waxing crescent Earth phase.

C) full Earth phase.

D) third-quarter Earth phase.

E) new Earth phase.

third-quarter Earth phase.

The wavelength of a wave is

A) how strong the wave is.

B) equal to the size of the object creating the wave.

C) the distance between two adjacent peaks of the wave.

D) the distance between a peak of the wave and the next trough.

E) the distance between where the wave is emitted and where it is absorbed.

the distance between two adjacent peaks of the wave.

Suppose the Sun were suddenly to shrink in size but that its mass remained the same. According to the law of conservation of angular momentum, what would happen?

A) The Sun would rotate faster than it does now.

B) The Sun’s angular size in our sky would stay the same.

C) This could never happen, because it is impossible for an object to shrink in size without an outside torque.

D) The Sun’s rate of motion would slow.

The Sun would rotate faster than it does now.

The ancient Greek astronomer Ptolemy put epicycles, or small circles on the larger circles, in his model of the Universe to explain

A) why we don’t see stellar parallax as Earth orbits the Sun.

B) why we don’t see a lunar eclipse every month.

C) why planets sometimes reverse direction and go west instead of east when compared to the “fixed” stars on the celestial sphere.

D) why the Moon appears so much larger than the planets.

E) why we don’t see a solar eclipse every month.

why planets sometimes reverse direction and go west instead of east when compared to the “fixed” stars on the celestial sphere.

Which of the following best describes the origin of ocean tides on Earth?

A) Tides are caused by the 23.5-degree tilt of the Earth’s rotational axis to the ecliptic plane.

B) The Moon’s gravity pulls harder on water than on land, because water is less dense than rock.

C) Tides are caused by the difference in the force of gravity exerted by the Moon across the sphere of the Earth.

D) Tides are caused on the side of the Earth nearest the Moon because the Moon’s gravity attracts the water.

Tides are caused by the difference in the force of gravity exerted by the Moon across the sphere of the Earth.

The amount of gravitational potential energy released as an object falls depends on

A) the distance it falls.

B) the distance it falls and its speed at the time it begins falling.

C)neither the distance it falls nor its speed at the time it begins falling.

D) its speed at the time it begins falling.

the distance it falls.

A television advertisement claiming that a product is light-years ahead of its time does not make sense because _____.

A) light-years can only be used to talk about light

B) it doesn’t specify the number of light-years

C) it uses “light-years” to talk about time, but a light-year is a unit of distance

D) a light-year is an astronomically large unit, so a product could not possibly be so advanced

it uses “light-years” to talk about time, but a light-year is a unit of distance

What is the difference between a bound orbit and an unbound orbit around the Sun?

A) An object on a bound orbit has a gravitational attraction to the Sun, while an object on an unbound orbit does not.

B) 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.

C) A bound orbit is an orbit allowed by the universal law of gravitation, and an unbound orbit is not.

D) A bound orbit is circular, while an unbound orbit is elliptical.

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.

While the historical definition of a constellation is “a pattern or figure of stars in the sky,” the modern definition used by astronomers is _____.

A) A specifically named and bordered region of the celestial sphere.

B) Any grouping of very bright stars in our galaxy, often hosting a star cluster.

C) No definition; astronomers no longer use the term constellation.

D) A group of stars in the sky that are all very close to each other.

A specifically named and bordered region of the celestial sphere.

If the Moon is setting at about 6 A.M., the phase of the moon must be _____.

A) full

B) third quarter

C) first quarter

D) new

E) waning crescent

full

42000 =

A) 4.2 × 10^5

B) 4.2 × 10^-4

C) 4.2 × 10^-3

D) 4.2 × 10^4

E) 4.2 × 10^3

4.2 × 10^4

Seasons on Earth are caused by _____.

A) the gravitational influence of the Moon

B) Earth’s varying orbital speed around the Sun

C) Earth’s axis tilt

D) the Sun’s gravity

E) Earth’s varying distance from the Sun

Earth’s axis tilt

The force of gravity between two masses is inversely proportional to the square of the distance between them. This means that if the distance between Earth and the Moon were made 3 times larger, the gravitational force of Earth on the Moon would be multiplied by

A) 1/9

B) 1/27

C) 3

D) 9

E) 1/3

1/9

What is the celestial equator?

A) A projection of Earth’s equator into space

B) Another name for the ecliptic

C) The technical name of the Sun’s equator

D) The path the Sun appears to trace through the constellations each year

A projection of Earth’s equator into space

In which general direction should you look to see the Moon set?

A) North

B) West

C) South

D) East

E) It depends on the phase of the Moon.

West

Imagine a planet at four points in its orbit around the Sun. At which point of the points shown is it traveling slowest in its orbit?

A) The point at which it is closest to the Sun.

B) The point at which it is farthest from the Sun.

The point at which it is farthest from the Sun.

Kepler’s third law, p² = a³, implies that _____.

A) the orbital period of a planet does not depend on its mass

B) planets that are farther from the Sun move at slower average speeds than nearer planets

C) a planet’s orbital period does not depend on the eccentricity of its orbit

D) all orbits with the same semimajor axis have the same period

E) All of the above are correct.

All of the above are correct.

Why did Ptolemy have the planets orbiting Earth on “circles upon circles” in his model of the universe?

A) To explain why Venus goes through phases as seen from Earth

B) To explain the fact that planets sometimes appear to move westward, rather than eastward, relative to the stars in our sky

C) To explain why the Greeks were unable to detect stellar parallax

D) To properly account for the varying distances of the planets from Earth

E) To explain why more distant planets take longer to make a circuit through the constellations of the zodiac

To explain the fact that planets sometimes appear to move westward, rather than eastward, relative to the stars in our sky

The controversial book On the Revolutions of the Celestial Spheres of this famous person, published in 1543 (the year of his death) suggested that Earth and other planets orbit the Sun.

A) Galileo

B) Ptolemy

C) Tycho Brahe

D) Kepler

E) Copernicus

Copernicus

Which of the following is not necessary of a good scientific theory?

A) A scientific theory must explain a wide variety of phenomena observed in the natural world.

B) A scientific theory must make testable predictions that, if found to be incorrect, could lead to its own modification or demise.

C) A scientific theory should be based on natural processes and should not invoke the supernatural or divine.

D) A scientific theory must be proven true beyond all doubt to be accepted.

A scientific theory must be proven true beyond all doubt to be accepted.

Which of the following is an example in which you are traveling at constant speed, but not at constant velocity?

A) Jumping up and down exactly 60 times per minute

B) Driving backward at exactly 50 km/hr

C) Driving around in a circle at exactly 100 km/hr

D) Rolling freely down a hill in a cart, traveling in a straight line

E) none of the above

Driving around in a circle at exactly 100 km/hr

Compared to their values on Earth, on another planet your

A) mass would be the same but your weight would be different.

B) mass and weight would both be different.

C) weight would be the same but your mass would be different.

D) mass and weight would both be the same.

mass would be the same but your weight would be different.

Why were ancient peoples unable to detect stellar parallax?

A) They did detect it, but they rejected the observations.

B) They did not observe for long enough periods of time.

C) They did not look for it.

D) They did not have the ability to measure very small angles.

E) They could not see distant stars.

They did not have the ability to measure very small angles.

Consider the statement “There is no gravity in space.” This statement is

A) completely true.

B) false if you’re close to a planet or moon, but true in between the planets.

C) completely false.

completely false.

Which person did the following? He tried fitting perfect circles to Tycho’s data, but in doing so found discrepancies of up to 8 arc minutes. Because he was confident that Tycho’s data had uncertainties of smaller than 1 arc minute, he abandoned perfect circles, which led him to a model using elliptical orbits.

A) Newton

B) Kepler

C) Galileo

D) Copernicus

Kepler

What is our place in the universe? Put in order:

Local Group

Solar System

Universe

Earth

Milky Way Galaxy

Local Supercluster

Earth, Solar System, Milk Way Galaxy, Local Group, Local Supercluster, Universe

Let’s reduce the size of the solar system by a factor of
10 billion; the Sun is now the size of a large grapefruit
(14 cm diameter).
How big is Earth on this scale?
A. an atom
B. a tip of a ballpoint pen
C. a marble
D. a golf ball

a tip of a ballpoint pen

Why does the Sun rise and set every
day?
A. The Earth orbits the Sun
B. The Earth spins on its axis
C. The Moon orbits the Earth
D. The Sun orbits the Earth
E. The Sun orbits the center of the Galaxy

The Earth spins on its axis

What causes the phases of the
Moon?
A. Earth’s shadow covering differing
portions of the Moon in its orbit.
B. Different amounts of sunlight hitting the
Moon in its orbit.
C. Differing fractions of the lighted part of
the Moon being visible from Earth.

Differing fractions of the lighted part of the Moon being visible from Earth.

The phases of the Moon are caused when
different portions of the Moon are covered by
Earth’s shadow.
A. True
B. False

False

A solar eclipse can happen during
A. a full moon
B. a new moon
C. a first quarter moon
D. either a full or a first quarter moon
E. either a full moon or a new moon

a new moon

Scientific thinking is
A. making predictions about future events
based on past observations and
experiences.
B. a gradual process of learning how the
world works.
C. a willingness to give up preconceived
notions if those ideas are inconsistent
with an experiment or observation.
D. all of the above

all of the above

How did the Greeks explain planetary motion?

Earth at the _____ of the universe.

center

Heavenly bodies move with uniform circular
motion: perfect circles at uniform speed.

False

Which of the following is NOT a fundamental
difference between the geocentric and Sun-centered
models of the solar system?

A. Earth is stationary in the geocentric model but moves
around the Sun in Sun-centered model.
B. Retrograde motion is real (planets really go backward) in
the geocentric model but only apparent (planets don’t
really turn around) in the Sun-centered model.
C. Stellar parallax is expected in the Sun-centered model but
not in the Earth-centered model.
D. The geocentric model is useless for predicting
planetary positions in the sky, whereas even the earliest
Sun-centered models worked almost perfectly.

The geocentric model is useless for predicting planetary positions in the sky, whereas even the earliest Sun-centered models worked almost perfectly.

The orbit of each planet around
the Sun is an ellipse with the Sun at one focus.

A) Kepler’s 1st Law

B) Kepler’s 2nd Law

C) Kepler’s 3rd Law

Kepler’s 1st Law

As a planet moves around its
orbit, it sweeps out equal areas in equal times.

A) Kepler’s 1st Law

B) Kepler’s 2nd Law

C) Kepler’s 3rd Law

Kepler’s 2nd Law

More distant planets orbit the Sun at slower
average speeds, obeying the relationship p² = a³.

A) Kepler’s 1st Law

B) Kepler’s 2nd Law

C) Kepler’s 3rd Law

Kepler’s 3rd Law

Which of Kepler’s laws tells us why a comet on a
very elliptical orbit spends most of its time way out
beyond the planets’ orbits?
A. 1st
B. 2nd
C. 3rd

2nd

Consider a planet orbiting the Sun. If the mass of
the planet doubled, but the planet kept the same
orbital distance, then the planet would take
A. more than twice as long to orbit the Sun.
B. exactly twice as long to orbit the Sun.
C. the same amount of time to orbit the
Sun.
D. exactly half as long to orbit the Sun.
E. less than half as long to orbit the Sun.

the same amount of time to orbit the Sun.

Modern science seeks explanations for
observed phenomena that rely solely on
natural causes.

A) Hallmarks of Science: #1

B) Hallmarks of Science: #2

C) Hallmarks of Science: #3

Hallmarks of Science: #1

Science progresses through the creation and
testing of models of nature that explain the
observations as simply as possible.

A) Hallmarks of Science: #1

B) Hallmarks of Science: #2

C) Hallmarks of Science: #3

Hallmarks of Science: #2

A scientific model must make testable
predictions about natural phenomena that
would force us to revise or abandon the
model if the predictions do not agree with
observations.

False

If we say a scientific model is a
theory, we mean that it
A. is just a guess.
B. has been tested repeatedly and has never
failed a test.
C. is absolutely 100% without a doubt true.

has been tested repeatedly and has never failed a test.

Darwin’s theory of evolution meets all the criteria of
a scientific theory. This means:

A. Scientific opinion is about evenly split as to whether
evolution really happened.
B. Scientific opinion runs about 90% in favor of the theory
of evolution and about 10% opposed.
C. After more than 100 years of testing, Darwin’s theory
stands stronger than ever, having successfully met
every scientific challenge to its validity.
D. There is no longer any doubt that the theory of evolution
is absolutely true.

After more than 100 years of testing, Darwin’s theory stands stronger than ever, having successfully met every scientific challenge to its validity.

What is pseudoscience?
A. Something that looks like science but isn’t.
B. Something that often uses scientific words but not the method of science.
C. Something that may want the respectability of science but does not
actually use the methods of science.
D. Something that usually doesn’t really work, or doesn’t work the way
claimed.
E. All of the above.

All of the above.

The great scientist and teacher, Richard
Feynman, said that science is “a way of trying
not to fool yourself.” What do you think he
meant?
A. Scientists are very smart. Become a scientist and you will know
more
B. It is natural to believe our own ideas, but not to want them
critically tested. Science forces us to test our ideas
C. Subconsciously we tend to see evidence that agrees with our ideas
and ignore that which doesn’t. In science, different groups of
scientists repeat experiments, removing some of this bias
D. All of the above
E. B and C

B and C

Is a net force acting on each of the following?
(Answer yes or no.)

A car coming to a stop:
A bus speeding up:
An elevator moving up at constant speed:
A bicycle going around a curve:
A moon orbiting Jupiter:

Yes, Yes, No, Yes, Yes

On the Moon,
A. your weight is the same; your mass is less.
B. your weight is less; your mass is the
same.
C. your weight is more; your mass is the
same.
D. your weight is more; your mass is less.

your weight is less; your mass is the same.

An object
moves at constant
velocity unless a net
force (Σ ≠ 0) acts to
change its speed and/or
direction.

A) Newton’s first law of motion

B) Newton’s second law of motion

C) Newton’s third law of motion

Newton’s first law of motion