PHY 102 Final Exam | Latest study set | Questions and
Answers | 2026 Updates | 100% correct
What is the speed of light? - ANSWER-Light can travel enormous distances under short periods
of time. It is faster than any other phenomenon. It takes about 8 minutes for light to travel from
the Sun to Earth. The speed of light in a vacuum is c=3x10^8 m/s.
Why is light such an important tool for astronomers? - ANSWER-Because light is how we learn
about distant objects without travelling there. It is also a measuring took of astronomy. Light is a
wave and a particle.
How are different kinds of light waves arranged in the EM spectrum? - ANSWER-Light is
arranged on the electromagnetic (EM) spectrum from shortest wavelength (highest energy) to
longest wavelength (lowest energy). The longer the wavelength the safer it is for people to be
around. Gamma rays have the shortest wavelength and are used for cancer radiation. X-Rays are
used for medical examinations. Infrared radiation is used in a TV remote, microwaves are used
in microwave ovens, and the radio waves are used in mobile phones. They are arranged by
frequency.
What is the relationship between frequency, color, wavelength, and energy? - ANSWER-Color is
how our eyes distinguish frequency. Speed of light equals frequency times wavelength. If
frequency gets big then wavelength gets smaller and vice versa. E=hf means if energy gets larger
so does frequency (because h is a constant). Frequency and wavelength are connected by speed
of light. If you know one of c=f(lambda) then you are able to calculate them all.
What do these equations express? c=f(lambda) and E=hf? - ANSWER-c=speed of light,
f=frequency, lambda=wavelength, C=f(lambda) is the equation of speed of light. For E=hf,
E=photon's energy, h=Planck's constant (6.67x10^-34 J) and f=frequency, This is the equation for
measuring a photon's energy.
What are the characteristics of a good scientific theory? - ANSWER-Good science involves
building upon existing knowledge, can be modified when new information is found, has
predictive power, develops step-by-step, is objective, and can be tested and disproved. Scientific
method steps: observe, hypothesize, predict, test, modify, and simplify. It has predictability, it
can be done repeatedly, and should be objective.
What might cause a scientific theory to be changed or abandoned? - ANSWER-If the theory is
not testable or if it has been disproved numerous times. It would also be abandoned if it is a
pseudoscience which means it is based off of non-developing facts or it is unable to be tested.
,What is the difference between a science and a pseudoscience? - ANSWER-Science is a process
and is testable and falsifiable, while a pseudoscience is usually impossible to disprove and rarely
has new developments. A pseudoscience has no test-ability, therefore it is not a science.
What units, and what size scales are needed to measure the universe? - ANSWER-Science is
generally done in the metric system, and different units are used for different measurements?
Why do stars, Sun, Moon and planets all appear to rise and set in our sky? - ANSWER-Because of
the way the Earth rotates on its axis. Depending on where you are on Earth, the movements of
the stars appear somewhat different.
What is the Celestial Sphere? How is the coordinate system set up? What are some of the major
features on the celestial sphere? - ANSWER-The celestial sphere is a fixed coordinate system to
model and map the sky: an imaginary sphere surrounding the Earth in which all objects in the
sky can be located. It has 2 axis points, the north and south celestial poles (located directly
above Earth's poles). There is also a celestial equator (directly above Earth's equator). Longitude
is measured in "right ascension" (in hours), latitude is "declination" (in degrees, minutes, and
seconds), and zero is the celestial equator.
What is the correct explanation for the phases of the Moon? - ANSWER-The relative angle
between the Sun, Moon, and Earth changes, illuminating the Moon's face differently.
What is the correct explanation for the seasons on Earth? - ANSWER-Earth's axis is tilted 23.5
degrees with respect to its orbit around the Sun. The tilt changes the seasons.
What is the cause of an eclipse? What kinds of eclipses are there? - ANSWER-There are lunar
eclipses (when the moon enters the shadow of the Earth). There are 3 types of lunar eclipses.
There is the penumbral eclipse (when the moon enters the penumbra of the Earth's shadow)
which is not very noticeable, a partial eclipse (when the moon is partially in the umbra), and the
moon is half dark, and a total lunar eclipse (when the whole Moon is in the Earth's umbra) and
the moon looks red. There are also solar eclipses (when the moon completely surpasses the
sun). There are partial solar eclipses (when the sun is only partially covered by the moon), and
Annular solar eclipses (when the Moon's umbra falls short of the Earth, the moon appears too
small to cover the Sun), these leave a thin ring, "annulus" of light around the moon.
What is the definition of velocity? How is it related to distance and time? - ANSWER-Velocity is
defined as "a quantity that specifies both direction and speed of an object." It is related to
distance and time because the equation for velocity is velocity=distance/time, meaning that
distance divided by time make up velocity.
What is the definition of acceleration? How is it related to velocity, distance, and time? -
ANSWER-A=V/t Acceleration is defined as "a charge in the direction or magnitude of a velocity."
, It is related to velocity, distance, and time because the equation for acceleration is a=(delta) v/t,
meaning that acceleration is the change in velocity (and distance factors into velocity) divided
by time.
What does this equation express? v=vo +at - ANSWER-This equation means: velocity=intial
velocity +constant x time.
What does this equation express? x=x0+v0t+½ at^2 - ANSWER-This is a kinematics equation
meaning: distance=initial displacement + initial velocity x time + constant x time squared. X is a
distance or position X0 is initial position, V0 is initial velocity. This equation figures out where an
object will be after certain time, velocity and with its initial position.
What property makes an atom unique, as opposed to other divisions of matter? - ANSWER-It is
because it is the smallest chemical properties? Each chemical element has it's own type of
atom, and if you break an atom up more it would not be that element anymore.
What is the structure of an atom? What are its constituent parts? What are the main features of
the Bohr model of an atom? - ANSWER-The modern view (Bohr model) has energy levels that
are very rigid and unique, energies in electrons are quantized meaning they can only have
certain energy levels. Nucleus has protons and neutrons and the number of protons tells the
chemical element while the number of neutrons tells the isotopes. Farthest electron has
maximum energy on the KLMN. Electrons can jump to different levels if turned on
What is an energy level in an atom? How do electrons move between them? - ANSWER-This is
part of Bohr's model, and the energy level is how much energy an electron has. Physicists used
to care about the placement of an electron, but lately they decided that placement does not
matter as much as energy level. Electrons can only move energy levels if the exact amount of
energy needed comes along. It was described like stairs, where you can't stand between 2 stairs,
you either have to be on one or the other.
What types of atoms are most important in studying astronomy? - ANSWER-Hydrogen and
helium because they are most abundant. 90% of the universe is hydrogen and 9% is helium.
What are galaxies made of? - ANSWER-They are made of hydrogen, helium, simple carbon
compounds, and most importantly gas and dust. These form stars and clouds of gas and dust
that are lit up by dust or will obscure the light from the stars.
How are galaxies classified? What type of galaxies are there? - ANSWER-Classified by Edwin
Hubble by how big they were through a telescope. Elliptical, Spiral, spiral barred, and irregular
. What is OUR galaxy called? What type of galaxy is it? - ANSWER-It is called the Milky Way and
it is a barred spiral galaxy. In the center of our galaxy is a supermassive black hole.
Answers | 2026 Updates | 100% correct
What is the speed of light? - ANSWER-Light can travel enormous distances under short periods
of time. It is faster than any other phenomenon. It takes about 8 minutes for light to travel from
the Sun to Earth. The speed of light in a vacuum is c=3x10^8 m/s.
Why is light such an important tool for astronomers? - ANSWER-Because light is how we learn
about distant objects without travelling there. It is also a measuring took of astronomy. Light is a
wave and a particle.
How are different kinds of light waves arranged in the EM spectrum? - ANSWER-Light is
arranged on the electromagnetic (EM) spectrum from shortest wavelength (highest energy) to
longest wavelength (lowest energy). The longer the wavelength the safer it is for people to be
around. Gamma rays have the shortest wavelength and are used for cancer radiation. X-Rays are
used for medical examinations. Infrared radiation is used in a TV remote, microwaves are used
in microwave ovens, and the radio waves are used in mobile phones. They are arranged by
frequency.
What is the relationship between frequency, color, wavelength, and energy? - ANSWER-Color is
how our eyes distinguish frequency. Speed of light equals frequency times wavelength. If
frequency gets big then wavelength gets smaller and vice versa. E=hf means if energy gets larger
so does frequency (because h is a constant). Frequency and wavelength are connected by speed
of light. If you know one of c=f(lambda) then you are able to calculate them all.
What do these equations express? c=f(lambda) and E=hf? - ANSWER-c=speed of light,
f=frequency, lambda=wavelength, C=f(lambda) is the equation of speed of light. For E=hf,
E=photon's energy, h=Planck's constant (6.67x10^-34 J) and f=frequency, This is the equation for
measuring a photon's energy.
What are the characteristics of a good scientific theory? - ANSWER-Good science involves
building upon existing knowledge, can be modified when new information is found, has
predictive power, develops step-by-step, is objective, and can be tested and disproved. Scientific
method steps: observe, hypothesize, predict, test, modify, and simplify. It has predictability, it
can be done repeatedly, and should be objective.
What might cause a scientific theory to be changed or abandoned? - ANSWER-If the theory is
not testable or if it has been disproved numerous times. It would also be abandoned if it is a
pseudoscience which means it is based off of non-developing facts or it is unable to be tested.
,What is the difference between a science and a pseudoscience? - ANSWER-Science is a process
and is testable and falsifiable, while a pseudoscience is usually impossible to disprove and rarely
has new developments. A pseudoscience has no test-ability, therefore it is not a science.
What units, and what size scales are needed to measure the universe? - ANSWER-Science is
generally done in the metric system, and different units are used for different measurements?
Why do stars, Sun, Moon and planets all appear to rise and set in our sky? - ANSWER-Because of
the way the Earth rotates on its axis. Depending on where you are on Earth, the movements of
the stars appear somewhat different.
What is the Celestial Sphere? How is the coordinate system set up? What are some of the major
features on the celestial sphere? - ANSWER-The celestial sphere is a fixed coordinate system to
model and map the sky: an imaginary sphere surrounding the Earth in which all objects in the
sky can be located. It has 2 axis points, the north and south celestial poles (located directly
above Earth's poles). There is also a celestial equator (directly above Earth's equator). Longitude
is measured in "right ascension" (in hours), latitude is "declination" (in degrees, minutes, and
seconds), and zero is the celestial equator.
What is the correct explanation for the phases of the Moon? - ANSWER-The relative angle
between the Sun, Moon, and Earth changes, illuminating the Moon's face differently.
What is the correct explanation for the seasons on Earth? - ANSWER-Earth's axis is tilted 23.5
degrees with respect to its orbit around the Sun. The tilt changes the seasons.
What is the cause of an eclipse? What kinds of eclipses are there? - ANSWER-There are lunar
eclipses (when the moon enters the shadow of the Earth). There are 3 types of lunar eclipses.
There is the penumbral eclipse (when the moon enters the penumbra of the Earth's shadow)
which is not very noticeable, a partial eclipse (when the moon is partially in the umbra), and the
moon is half dark, and a total lunar eclipse (when the whole Moon is in the Earth's umbra) and
the moon looks red. There are also solar eclipses (when the moon completely surpasses the
sun). There are partial solar eclipses (when the sun is only partially covered by the moon), and
Annular solar eclipses (when the Moon's umbra falls short of the Earth, the moon appears too
small to cover the Sun), these leave a thin ring, "annulus" of light around the moon.
What is the definition of velocity? How is it related to distance and time? - ANSWER-Velocity is
defined as "a quantity that specifies both direction and speed of an object." It is related to
distance and time because the equation for velocity is velocity=distance/time, meaning that
distance divided by time make up velocity.
What is the definition of acceleration? How is it related to velocity, distance, and time? -
ANSWER-A=V/t Acceleration is defined as "a charge in the direction or magnitude of a velocity."
, It is related to velocity, distance, and time because the equation for acceleration is a=(delta) v/t,
meaning that acceleration is the change in velocity (and distance factors into velocity) divided
by time.
What does this equation express? v=vo +at - ANSWER-This equation means: velocity=intial
velocity +constant x time.
What does this equation express? x=x0+v0t+½ at^2 - ANSWER-This is a kinematics equation
meaning: distance=initial displacement + initial velocity x time + constant x time squared. X is a
distance or position X0 is initial position, V0 is initial velocity. This equation figures out where an
object will be after certain time, velocity and with its initial position.
What property makes an atom unique, as opposed to other divisions of matter? - ANSWER-It is
because it is the smallest chemical properties? Each chemical element has it's own type of
atom, and if you break an atom up more it would not be that element anymore.
What is the structure of an atom? What are its constituent parts? What are the main features of
the Bohr model of an atom? - ANSWER-The modern view (Bohr model) has energy levels that
are very rigid and unique, energies in electrons are quantized meaning they can only have
certain energy levels. Nucleus has protons and neutrons and the number of protons tells the
chemical element while the number of neutrons tells the isotopes. Farthest electron has
maximum energy on the KLMN. Electrons can jump to different levels if turned on
What is an energy level in an atom? How do electrons move between them? - ANSWER-This is
part of Bohr's model, and the energy level is how much energy an electron has. Physicists used
to care about the placement of an electron, but lately they decided that placement does not
matter as much as energy level. Electrons can only move energy levels if the exact amount of
energy needed comes along. It was described like stairs, where you can't stand between 2 stairs,
you either have to be on one or the other.
What types of atoms are most important in studying astronomy? - ANSWER-Hydrogen and
helium because they are most abundant. 90% of the universe is hydrogen and 9% is helium.
What are galaxies made of? - ANSWER-They are made of hydrogen, helium, simple carbon
compounds, and most importantly gas and dust. These form stars and clouds of gas and dust
that are lit up by dust or will obscure the light from the stars.
How are galaxies classified? What type of galaxies are there? - ANSWER-Classified by Edwin
Hubble by how big they were through a telescope. Elliptical, Spiral, spiral barred, and irregular
. What is OUR galaxy called? What type of galaxy is it? - ANSWER-It is called the Milky Way and
it is a barred spiral galaxy. In the center of our galaxy is a supermassive black hole.
