Question 1

Light is increasingly redshifted near a black hole because:

Accepted Answer

A)  the photons are moving away from us very quickly as they are sucked into the black hole. 
B)  the photons are moving increasingly faster in order to escape the pull of the black hole. 
C)  time is moving increasingly slower in the observer's frame of reference. 
D)  the curvature of spacetime is increasingly stretched near the black hole, which in turn stretches the wavelengths of the photons. 
A)  the photons are moving away from us very quickly as they are sucked into the black hole. 
B)  the photons are moving increasingly faster in order to escape the pull of the black hole. 
C)  time is moving increasingly slower in the observer's frame of reference. 
D)  the curvature of spacetime is increasingly stretched near the black hole, which in turn stretches the wavelengths of the photons. C

Question 2

An astronaut would feel ________ as he or she crossed the event horizon of a stellar black hole.

Accepted Answer

A)  incredibly strong tidal forces 
B)  intense heating 
C)  lighter 
D)  nothing 
A)  incredibly strong tidal forces 
B)  intense heating 
C)  lighter 
D)  nothing A

Question 3

A Cepheid star varies in luminosity because the:

Accepted Answer

A)  entire star pulsates from its core to its surface. 
B)  outer envelope of the star pulsates. 
C)  star rotates too quickly. 
D)  star is too massive to be stable. 
A)  entire star pulsates from its core to its surface. 
B)  outer envelope of the star pulsates. 
C)  star rotates too quickly. 
D)  star is too massive to be stable. B

Question 4

In the figure below,when elements from section A undergo fusion,energy is ________.Because of this fact,it would be ________ to find a high-mass main-sequence star with a high concentration of elements from section B.

Accepted Answer

A)  released; likely 
B)  absorbed; likely 
C)  released; unlikely 
D)  absorbed; unlikely 
A)  released; likely 
B)  absorbed; likely 
C)  released; unlikely 
D)  absorbed; unlikely

Question 5

The equivalence principle says that:

Accepted Answer

A)  being stationary in a gravitational field is the same as being in an accelerated reference frame. 
B)  the universe is homogeneous and isotropic. 
C)  at any radius inside a star, the outward gas pressure must balance the weight of the material on top. 
D)  mass and energy are interchangeable, and neither can be destroyed. 
A)  being stationary in a gravitational field is the same as being in an accelerated reference frame. 
B)  the universe is homogeneous and isotropic. 
C)  at any radius inside a star, the outward gas pressure must balance the weight of the material on top. 
D)  mass and energy are interchangeable, and neither can be destroyed.

Question 6

Why do main-sequence high-mass stars lose so much mass compared to low-mass stars?

Accepted Answer

They have very strong winds because thei

Question 7

The figure below shows the relative abundances of different elements on Earth.Explain why elements less massive than iron are,in general,most common,why there is a small peak at iron,and why elements more massive than iron are less common.

Accepted Answer

Elements less massive than iron are comm

Question 8

Hawking radiation is emitted by a black hole when:

Accepted Answer

A)  the black hole rotates quickly. 
B)  the black hole accretes material. 
C)  a virtual pair of particles is created from the vacuum of space. 
D)  synchrotron radiation is emitted by infalling charged particles. 
A)  the black hole rotates quickly. 
B)  the black hole accretes material. 
C)  a virtual pair of particles is created from the vacuum of space. 
D)  synchrotron radiation is emitted by infalling charged particles.

Question 9

________ is the result of mass distorting the fabric of spacetime.

Accepted Answer

A)  Energy 
B)  Radiation 
C)  Fusion 
D)  Gravity 
A)  Energy 
B)  Radiation 
C)  Fusion 
D)  Gravity

Question 10

Once carbon begins burning in the core of a high-mass star,the outer layers begin to fall inward,driving up the fusion rates and speeding up the star's evolution primarily because:

Accepted Answer

A)  the number of particles in the core is decreasing, which now take up less space. 
B)  most of the energy is now carried away from the core by escaping neutrinos, which have few if any obstacles to leaving the star. 
C)  carbon is a more stable element that appears to settle the star. 
D)  the light given off by the fusion of carbon is a different wavelength than that given off by previous reactions, so the radiation pressure is much smaller. 
A)  the number of particles in the core is decreasing, which now take up less space. 
B)  most of the energy is now carried away from the core by escaping neutrinos, which have few if any obstacles to leaving the star. 
C)  carbon is a more stable element that appears to settle the star. 
D)  the light given off by the fusion of carbon is a different wavelength than that given off by previous reactions, so the radiation pressure is much smaller.

Question 11

Once silicon burning begins to fuse iron in the core of a high-mass main-sequence star,it only has a few ________ left to live.

Accepted Answer

A)  seconds 
B)  days 
C)  months 
D)  years 
A)  seconds 
B)  days 
C)  months 
D)  years

Question 12

Show where stars are variable in brightness in the figure below.What is this region called?

Accepted Answer

The answer of Show where stars are variable in brightness...

Question 13

Examine the figure of a pulsar below.What are pulsars,and what circumstance must Earth be in for astronomers to observe one?

Accepted Answer

Pulsars are neutron stars that

Question 14

While traveling the galaxy in a spacecraft,you and a colleague set out to investigate a 1-M¤ black hole.Your colleague hops aboard an escape pod and drops into a circular orbit around the black hole maintaining a distance of 10 km from it,while you remain much farther away inside the spacecraft.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,and why?

Accepted Answer

The event horizon is at a radius of 3 km

Question 15

Photons have no mass,and Einstein's theory of general relativity says:

Accepted Answer

A)  their paths through spacetime are curved in the presence of a massive body. 
B)  their apparent speeds depend on the observer's frame of reference. 
C)  they should not be attracted to a massive object. 
D)  their wavelengths must remain the same as they travel through spacetime. 
A)  their paths through spacetime are curved in the presence of a massive body. 
B)  their apparent speeds depend on the observer's frame of reference. 
C)  they should not be attracted to a massive object. 
D)  their wavelengths must remain the same as they travel through spacetime.

Question 16

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,which muon is most likely to be detected on the ground?

Accepted Answer

A)  muon A 
B)  muon B 
C)  muon C 
D)  muon D 
A)  muon A 
B)  muon B 
C)  muon C 
D)  muon D

Question 17

Which of the following is NOT a common characteristic of a neutron star?

Accepted Answer

A)  extremely high density 
B)  enormous magnetic field 
C)  very short rotation period 
D)  All of these are common characteristics of a neutron star. 
A)  extremely high density 
B)  enormous magnetic field 
C)  very short rotation period 
D)  All of these are common characteristics of a neutron star.

Question 18

Which of the following is true about the instability strip on the H-R diagram?

Accepted Answer

A)  evolved stars pulsate 
B)  location of RR Lyrae and Cepheids 
C)  stars show variability in their brightness 
D)  all of the above 
A)  evolved stars pulsate 
B)  location of RR Lyrae and Cepheids 
C)  stars show variability in their brightness 
D)  all of the above

Question 19

The collapse of the core of a high-mass star at the end of its life lasts approximately:

Accepted Answer

A)  1 second. 
B)  1 hour. 
C)  1 week. 
D)  1 year. 
A)  1 second. 
B)  1 hour. 
C)  1 week. 
D)  1 year.

Question 20

What supports a neutron star from collapsing to form a black hole?

Accepted Answer

The pressure from de

Light is increasingly redshifted near a black hole because:

An astronaut would feel ________ as he or she crossed the event horizon of a stellar black hole.

A Cepheid star varies in luminosity because the:

In the figure below,when elements from section A undergo fusion,energy is .Because of this fact,it would be to find a high-mass main-sequence star with a high concentration of elements from section B.

The equivalence principle says that:

Why do main-sequence high-mass stars lose so much mass compared to low-mass stars?

The figure below shows the relative abundances of different elements on Earth.Explain why elements less massive than iron are,in general,most common,why there is a small peak at iron,and why elements more massive than iron are less common.

Hawking radiation is emitted by a black hole when:

________ is the result of mass distorting the fabric of spacetime.

Once carbon begins burning in the core of a high-mass star,the outer layers begin to fall inward,driving up the fusion rates and speeding up the star's evolution primarily because:

Once silicon burning begins to fuse iron in the core of a high-mass main-sequence star,it only has a few ________ left to live.

Show where stars are variable in brightness in the figure below.What is this region called?

Examine the figure of a pulsar below.What are pulsars,and what circumstance must Earth be in for astronomers to observe one?

Photons have no mass,and Einstein's theory of general relativity says:

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,which muon is most likely to be detected on the ground?

Which of the following is NOT a common characteristic of a neutron star?

Which of the following is true about the instability strip on the H-R diagram?

The collapse of the core of a high-mass star at the end of its life lasts approximately:

What supports a neutron star from collapsing to form a black hole?

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

Light is increasingly redshifted near a black hole because:

An astronaut would feel ________ as he or she crossed the event horizon of a stellar black hole.

A Cepheid star varies in luminosity because the:

In the figure below,when elements from section A undergo fusion,energy is ________.Because of this fact,it would be ________ to find a high-mass main-sequence star with a high concentration of elements from section B.

The equivalence principle says that:

Why do main-sequence high-mass stars lose so much mass compared to low-mass stars?

The figure below shows the relative abundances of different elements on Earth.Explain why elements less massive than iron are,in general,most common,why there is a small peak at iron,and why elements more massive than iron are less common.

Hawking radiation is emitted by a black hole when:

________ is the result of mass distorting the fabric of spacetime.

Once carbon begins burning in the core of a high-mass star,the outer layers begin to fall inward,driving up the fusion rates and speeding up the star's evolution primarily because:

Once silicon burning begins to fuse iron in the core of a high-mass main-sequence star,it only has a few ________ left to live.

Show where stars are variable in brightness in the figure below.What is this region called?

Examine the figure of a pulsar below.What are pulsars,and what circumstance must Earth be in for astronomers to observe one?

Photons have no mass,and Einstein's theory of general relativity says:

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,which muon is most likely to be detected on the ground?

Which of the following is NOT a common characteristic of a neutron star?

Which of the following is true about the instability strip on the H-R diagram?

The collapse of the core of a high-mass star at the end of its life lasts approximately:

What supports a neutron star from collapsing to form a black hole?

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

In the figure below,when elements from section A undergo fusion,energy is .Because of this fact,it would be to find a high-mass main-sequence star with a high concentration of elements from section B.