Question 1

Which of the following is a consequence of Einstein's special theory of relativity?

Accepted Answer

A)  Moving clocks run quicker. 
B)  The velocity of light depends on the speed of the observer. 
C)  Distances appear shorter when traveling near the speed of light. 
D)  Gravity arises because mass distorts spacetime. 
A)  Moving clocks run quicker. 
B)  The velocity of light depends on the speed of the observer. 
C)  Distances appear shorter when traveling near the speed of light. 
D)  Gravity arises because mass distorts spacetime.

Question 2

Examine the figure below.Explain what the equivalence principle is in general relativity.

Accepted Answer

The equivalence principle is the idea th

Question 3

The main difference between Cepheid variable stars and RR Lyrae stars is:

Accepted Answer

A)  their pulsation mechanisms. 
B)  their masses. 
C)  that Cepheids form at much greater distances from Earth. 
D)  that RR Lyrae were discovered much earlier than Cepheids. 
A)  their pulsation mechanisms. 
B)  their masses. 
C)  that Cepheids form at much greater distances from Earth. 
D)  that RR Lyrae were discovered much earlier than Cepheids.

Question 4

Why do large,high-mass main-sequence stars never become red giants?

Accepted Answer

When high-mass stars begin bur

Question 5

If an 8-M¤ star loses mass at an average rate of 10⁻⁶ M¤/year in a stellar wind,how many years would it take for its mass to be reduced to 6 M¤? Would this amount of mass loss be possible in the star's lifetime?

Accepted Answer

If R is the mass loss rate and M is the

Question 6

A neutron star contains a mass of up to 3 M¤ in a sphere with a diameter approximately the size of:

Accepted Answer

A)  an atomic nucleus. 
B)  a school bus. 
C)  a city. 
D)  Earth. 
A)  an atomic nucleus. 
B)  a school bus. 
C)  a city. 
D)  Earth.

Question 7

What would happen if mass were continually added to a 2-M¤ neutron star?

Accepted Answer

A)  The star's radius would increase. 
B)  The star would eventually become a black hole. 
C)  The star would erupt as a nova. 
D)  All of the above would occur. 
A)  The star's radius would increase. 
B)  The star would eventually become a black hole. 
C)  The star would erupt as a nova. 
D)  All of the above would occur.

Question 8

If the Sun were to be instantly replaced by a 1-M¤ black hole,the gravitational pull of the black hole on Earth would be:

Accepted Answer

A)  much greater than it is now. 
B)  the same as it is now. 
C)  much smaller than it is now. 
D)  irrelevant because Earth would be quickly obliterated by the strong tidal force of the black hole. 
A)  much greater than it is now. 
B)  the same as it is now. 
C)  much smaller than it is now. 
D)  irrelevant because Earth would be quickly obliterated by the strong tidal force of the black hole.

Question 9

Gravitational lensing occurs when ________ distorts the fabric of spacetime.

Accepted Answer

A)  a star 
B)  dark matter 
C)  a black hole 
D)  any massive object 
A)  a star 
B)  dark matter 
C)  a black hole 
D)  any massive object

Question 10

If Earth were to be condensed down in size until it became a black hole,its Schwarzschild radius would be:

Accepted Answer

A)  1 cm. 
B)  1 meter. 
C)  1 km. 
D)  10 km. 
A)  1 cm. 
B)  1 meter. 
C)  1 km. 
D)  10 km.

Question 11

Although a Type II supernova shines with a luminosity of 100 billion L¤,most of the energy in the explosion is emitted in another way.What is it,and how much more energy does it carry compared to the light?

Accepted Answer

The majority of the energy released in a

Question 12

While traveling the galaxy in a spacecraft,you and a colleague set out to investigate the 10⁶-M¤ black hole at the center of our galaxy.Your colleague hops aboard an escape pod and drops into a circular orbit around the black hole,maintaining a distance of 1 AU,while you remain much farther away in the spacecraft but from which you can easily monitor your colleague.After doing some experiments to measure the strength of gravity,your colleague signals the results back to you using a green laser.What would you see?

Accepted Answer

A)  the signals, because he or she is orbiting well outside the event horizon 
B)  the signals, but shifted to a much redder wavelength because he or she is very close to the event horizon 
C)  nothing, because your colleague has crossed the event horizon 
D)  nothing, because no light can escape the gravitational pull of a black hole no matter how close the signal is to it 
A)  the signals, because he or she is orbiting well outside the event horizon 
B)  the signals, but shifted to a much redder wavelength because he or she is very close to the event horizon 
C)  nothing, because your colleague has crossed the event horizon 
D)  nothing, because no light can escape the gravitational pull of a black hole no matter how close the signal is to it

Question 13

If a 60-M¤ main-sequence star loses mass at a rate of 10⁻⁴ M¤/year,then how much mass will it lose in its 300,000-year lifetime?

Accepted Answer

A)  3 M¤ 
B)  8 M¤ 
C)  10 M¤ 
D)  30 M¤ 
A)  3 M¤ 
B)  8 M¤ 
C)  10 M¤ 
D)  30 M¤

Question 14

Why are Type II supernova not good distance indicators like those of Type Ia?

Accepted Answer

A type II supernova is the result of a m

Question 15

What is the difference between the singularity and the event horizon of a black hole?

Accepted Answer

The singularity is the very center of th

Question 16

As a high-mass main-sequence star evolves off the main sequence,it follows a ________ on the H-R diagram.

Accepted Answer

A)  nearly vertical path 
B)  path of constant radius 
C)  roughly horizontal path 
D)  None of the above answers is correct. 
A)  nearly vertical path 
B)  path of constant radius 
C)  roughly horizontal path 
D)  None of the above answers is correct.

Question 17

An iron core cannot support a massive main-sequence star because iron:

Accepted Answer

A)  has poor nuclear binding energy. 
B)  cannot fuse with other nuclei to produce energy. 
C)  supplies too much pressure. 
D)  fusion only occurs in a degenerate core. 
A)  has poor nuclear binding energy. 
B)  cannot fuse with other nuclei to produce energy. 
C)  supplies too much pressure. 
D)  fusion only occurs in a degenerate core.

Question 18

Assume that a group of explorers traveled to the Orion Nebula,the nearest star-forming cloud at a distance of 1,300 light-years,using revolutionary technology that allowed them to travel at a speed very close to the speed of light.Observers back on Earth would say it took them ________ to get there,but the travelers would say it took them ________ to get there.

Accepted Answer

A)  slightly more than 1,300 years; much less than 1,300 years 
B)  slightly more than 1,300 years; slightly less than 1,300 years 
C)  slightly less than 1,300 years; slightly more than 1,300 years 
D)  exactly 1,300 years; much less than 1,300 years 
A)  slightly more than 1,300 years; much less than 1,300 years 
B)  slightly more than 1,300 years; slightly less than 1,300 years 
C)  slightly less than 1,300 years; slightly more than 1,300 years 
D)  exactly 1,300 years; much less than 1,300 years

Question 19

Normally,muons created by cosmic rays at high altitudes decay in a very short time,a time so short that they should not reach the ground.From the figure below,why does increasing speed of muons created by cosmic rays at high altitudes mean that additional muons will reach the ground before decaying?

Accepted Answer

A faster speed for a muon tran

Question 20

Name at least two processes that speed the collapse of the core of a dying high-mass star.

Accepted Answer

The answer should include at least two o

Which of the following is a consequence of Einstein's special theory of relativity?

Examine the figure below.Explain what the equivalence principle is in general relativity.

The main difference between Cepheid variable stars and RR Lyrae stars is:

Why do large,high-mass main-sequence stars never become red giants?

If an 8-M¤ star loses mass at an average rate of 10⁻⁶ M¤/year in a stellar wind,how many years would it take for its mass to be reduced to 6 M¤? Would this amount of mass loss be possible in the star's lifetime?

A neutron star contains a mass of up to 3 M¤ in a sphere with a diameter approximately the size of:

What would happen if mass were continually added to a 2-M¤ neutron star?

If the Sun were to be instantly replaced by a 1-M¤ black hole,the gravitational pull of the black hole on Earth would be:

Gravitational lensing occurs when ________ distorts the fabric of spacetime.

If Earth were to be condensed down in size until it became a black hole,its Schwarzschild radius would be:

Although a Type II supernova shines with a luminosity of 100 billion L¤,most of the energy in the explosion is emitted in another way.What is it,and how much more energy does it carry compared to the light?

If a 60-M¤ main-sequence star loses mass at a rate of 10⁻⁴ M¤/year,then how much mass will it lose in its 300,000-year lifetime?

Why are Type II supernova not good distance indicators like those of Type Ia?

What is the difference between the singularity and the event horizon of a black hole?

As a high-mass main-sequence star evolves off the main sequence,it follows a ________ on the H-R diagram.

An iron core cannot support a massive main-sequence star because iron:

Normally,muons created by cosmic rays at high altitudes decay in a very short time,a time so short that they should not reach the ground.From the figure below,why does increasing speed of muons created by cosmic rays at high altitudes mean that additional muons will reach the ground before decaying?

Name at least two processes that speed the collapse of the core of a dying high-mass star.

Thinking Like an Astronomer

Patterns in the Skymotions of Earth and the Moon

Laws of Motion

Light and Telescopes

The Formation of Stars and Planets

Terrestrial Worlds in the Inner Solar System

Atmospheres of Venus, earth, and Mars

The Giant Planets

Small Bodies of the Solar System

Measuring the Stars

Our Star: the Sun

Evolution of Low-Mass Stars

Measuring Galaxies

Our Galaxy: the Milky Way

The Evolution of the Universe

Formation of Structure

Life in the Universe

Filters

Exam 13: Evolution of High-Mass Stars

Which of the following is a consequence of Einstein's special theory of relativity?

Examine the figure below.Explain what the equivalence principle is in general relativity.

The main difference between Cepheid variable stars and RR Lyrae stars is:

Why do large,high-mass main-sequence stars never become red giants?

If an 8-M¤ star loses mass at an average rate of 10⁻⁶ M¤/year in a stellar wind,how many years would it take for its mass to be reduced to 6 M¤? Would this amount of mass loss be possible in the star's lifetime?

A neutron star contains a mass of up to 3 M¤ in a sphere with a diameter approximately the size of:

What would happen if mass were continually added to a 2-M¤ neutron star?

If the Sun were to be instantly replaced by a 1-M¤ black hole,the gravitational pull of the black hole on Earth would be:

Gravitational lensing occurs when ________ distorts the fabric of spacetime.

If Earth were to be condensed down in size until it became a black hole,its Schwarzschild radius would be:

Although a Type II supernova shines with a luminosity of 100 billion L¤,most of the energy in the explosion is emitted in another way.What is it,and how much more energy does it carry compared to the light?

If a 60-M¤ main-sequence star loses mass at a rate of 10⁻⁴ M¤/year,then how much mass will it lose in its 300,000-year lifetime?

Why are Type II supernova not good distance indicators like those of Type Ia?

What is the difference between the singularity and the event horizon of a black hole?

As a high-mass main-sequence star evolves off the main sequence,it follows a ________ on the H-R diagram.

An iron core cannot support a massive main-sequence star because iron:

Name at least two processes that speed the collapse of the core of a dying high-mass star.

Thinking Like an Astronomer

Patterns in the Skymotions of Earth and the Moon

Laws of Motion

Light and Telescopes

The Formation of Stars and Planets

Terrestrial Worlds in the Inner Solar System

Atmospheres of Venus, earth, and Mars

The Giant Planets

Small Bodies of the Solar System

Measuring the Stars

Our Star: the Sun

Evolution of Low-Mass Stars

Measuring Galaxies

Our Galaxy: the Milky Way

The Evolution of the Universe

Formation of Structure

Life in the Universe

Filters