Question 1

Relate escape velocity to the event horizon.

Accepted Answer

At the event horizon around a

Question 2

How can a black hole of a few solar masses be detected?

Accepted Answer

Look for a binary system in which one bo

Question 3

Why is the light from near a black hole redshifted?

Accepted Answer

The gravity is great enough to

Question 4

If a specially designed space probe reaches the event horizon of a black hole, an observer watching the clock on this probe from a safe distance would see

Accepted Answer

A)  the clock slow down. 
B)  the clock speed up. 
C)  the clock keep time in sync with the observer's clock. 
D)  the time on the clock would appear to change randomly. 
A)  the clock slow down. 
B)  the clock speed up. 
C)  the clock keep time in sync with the observer's clock. 
D)  the time on the clock would appear to change randomly.

Question 5

The largest known black holes

Accepted Answer

A)  create the dark nebulae in the plane of the Milky Way. 
B)  can be no more than 1.4 solar masses, according to Chandrasekhar. 
C)  lie in the cores of the most massive galaxies. 
D)  can be no bigger than a small city, just like neutron stars. 
E)  can be no bigger than the Earth, like white dwarfs. 
A)  create the dark nebulae in the plane of the Milky Way. 
B)  can be no more than 1.4 solar masses, according to Chandrasekhar. 
C)  lie in the cores of the most massive galaxies. 
D)  can be no bigger than a small city, just like neutron stars. 
E)  can be no bigger than the Earth, like white dwarfs.

Question 6

Why do scientists describe the theory of gravity as "incomplete"?

Accepted Answer

A)  It does not incorporate a description of matter on a very small scale. 
B)  It does not explain why light bends near a dense object. 
C)  It does not agree with the expansion of the universe. 
D)  The gravity waves it predicts have not been observed. 
E)  It does not explain the effects on time from a massive object. 
A)  It does not incorporate a description of matter on a very small scale. 
B)  It does not explain why light bends near a dense object. 
C)  It does not agree with the expansion of the universe. 
D)  The gravity waves it predicts have not been observed. 
E)  It does not explain the effects on time from a massive object.

Question 7

The curvature of spacetime around a black hole is so extreme that outward-going signals cannot escape.

Accepted Answer

A) True 
 B)False

Question 8

Relate escape speed to event horizon for a black hole.

Accepted Answer

The escape speed allows an object moving

Question 9

Which of the following can actually escape from inside a black hole's event horizon?

Accepted Answer

A)  Neutrinos 
B)  Electrons 
C)  Very high energy gamma-rays 
D)  Protons 
E)  None of the above 
A)  Neutrinos 
B)  Electrons 
C)  Very high energy gamma-rays 
D)  Protons 
E)  None of the above

Question 10

The equivalence principle says that a person in an elevator that is in freefall feels the same acceleration as

Accepted Answer

A)  a person in an elevator going up with an acceleration of g. 
B)  a person in space, far from any gravitational source accelerating at g. 
C)  a person in an elevator going down with an acceleration of g. 
D)  a person in space, far away from any gravitational source with no acceleration. 
E)  a person in orbit of Earth accelerating at g upward. 
A)  a person in an elevator going up with an acceleration of g. 
B)  a person in space, far from any gravitational source accelerating at g. 
C)  a person in an elevator going down with an acceleration of g. 
D)  a person in space, far away from any gravitational source with no acceleration. 
E)  a person in orbit of Earth accelerating at g upward.

Question 11

The key to identifying a black hole candidate in a binary system is that

Accepted Answer

A)  one of the two stars cannot be seen. 
B)  the unseen companion in the system must have a sufficiently high mass. 
C)  the unseen star is a contact binary. 
D)  the system must be a very strong source of radio emissions. 
E)  the visible companion must be an evolving main sequence or giant star. 
A)  one of the two stars cannot be seen. 
B)  the unseen companion in the system must have a sufficiently high mass. 
C)  the unseen star is a contact binary. 
D)  the system must be a very strong source of radio emissions. 
E)  the visible companion must be an evolving main sequence or giant star.

Question 12

The Schwartzschild radius for a 12 solar mass star is

Accepted Answer

A)  4 km. 
B)  15 km. 
C)  36 km. 
D)  100 km. 
E)  3000 km. 
A)  4 km. 
B)  15 km. 
C)  36 km. 
D)  100 km. 
E)  3000 km.

Question 13

On a sphere, the interior angles of a triangle add up to ________ 180 degrees.

Accepted Answer

The answer of On a sphere, the interior angles of...

Question 14

A ________ is a place where the current rules fall apart in science.

Accepted Answer

The answer of A ________ is a place where the...

Question 15

Einstein earned the Nobel Prize for his

Accepted Answer

A)  special theory of relativity. 
B)  general theory of relativity. 
C)  development of the equivalence of energy and matter, E = mc². 
D)  work on the particle nature of light. 
E)  contributions to the development of the fission bomb. 
A)  special theory of relativity. 
B)  general theory of relativity. 
C)  development of the equivalence of energy and matter, E = mc². 
D)  work on the particle nature of light. 
E)  contributions to the development of the fission bomb.

Question 16

Any main sequence star over 25 solar masses will probably retain enough matter in its core after its type II supernova to make a black hole.

Accepted Answer

A) True 
 B)False

Question 17

Black holes with masses greater than a million solar masses explain the extremely rapidly moving stars and gas in the cores of galaxies.

Accepted Answer

A) True 
 B)False

Question 18

Only neutrinos can go faster than the speed of light.

Accepted Answer

A) True 
 B)False

Question 19

In a vacuum, which form of electromagnetic radiation travels slowest?

Accepted Answer

A)  Visible light 
B)  Radio 
C)  Gamma rays 
D)  Ultraviolet light 
E)  All forms of electromagnetic radiation travel at the same speed. 
A)  Visible light 
B)  Radio 
C)  Gamma rays 
D)  Ultraviolet light 
E)  All forms of electromagnetic radiation travel at the same speed.

Question 20

What are the three possible outcomes of stellar evolution? Describe each possibility, differentiating their means of formation and their subsequent properties. Which stars on the Main Sequence are thought to end up in each of these forms?

Accepted Answer

If less than 1.4 solar masses the final

Relate escape velocity to the event horizon.

How can a black hole of a few solar masses be detected?

Why is the light from near a black hole redshifted?

If a specially designed space probe reaches the event horizon of a black hole, an observer watching the clock on this probe from a safe distance would see

The largest known black holes

Why do scientists describe the theory of gravity as "incomplete"?

The curvature of spacetime around a black hole is so extreme that outward-going signals cannot escape.

Relate escape speed to event horizon for a black hole.

Which of the following can actually escape from inside a black hole's event horizon?

The equivalence principle says that a person in an elevator that is in freefall feels the same acceleration as

The key to identifying a black hole candidate in a binary system is that

The Schwartzschild radius for a 12 solar mass star is

On a sphere, the interior angles of a triangle add up to ________ 180 degrees.

A ________ is a place where the current rules fall apart in science.

Einstein earned the Nobel Prize for his

Any main sequence star over 25 solar masses will probably retain enough matter in its core after its type II supernova to make a black hole.

Black holes with masses greater than a million solar masses explain the extremely rapidly moving stars and gas in the cores of galaxies.

Only neutrinos can go faster than the speed of light.

In a vacuum, which form of electromagnetic radiation travels slowest?

What are the three possible outcomes of stellar evolution? Describe each possibility, differentiating their means of formation and their subsequent properties. Which stars on the Main Sequence are thought to end up in each of these forms?

The Night Sky

Light and Telescopes

The Solar System

Earth and Its Moon

The Eight Planets

Small Bodies in the Solar System

Formation of Planetary Systems

The Sun

Measuring the Stars

Star Formation and Evolution

Stellar Explosions

The Milky Way Galaxy

Galaxies

Cosmology and the Universe

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Exam 12: Black Holes

Relate escape velocity to the event horizon.

How can a black hole of a few solar masses be detected?

Why is the light from near a black hole redshifted?

If a specially designed space probe reaches the event horizon of a black hole, an observer watching the clock on this probe from a safe distance would see

The largest known black holes

Why do scientists describe the theory of gravity as "incomplete"?

The curvature of spacetime around a black hole is so extreme that outward-going signals cannot escape.

Relate escape speed to event horizon for a black hole.

Which of the following can actually escape from inside a black hole's event horizon?

The equivalence principle says that a person in an elevator that is in freefall feels the same acceleration as

The key to identifying a black hole candidate in a binary system is that

The Schwartzschild radius for a 12 solar mass star is

On a sphere, the interior angles of a triangle add up to ________ 180 degrees.

A ________ is a place where the current rules fall apart in science.

Einstein earned the Nobel Prize for his

Any main sequence star over 25 solar masses will probably retain enough matter in its core after its type II supernova to make a black hole.

Black holes with masses greater than a million solar masses explain the extremely rapidly moving stars and gas in the cores of galaxies.

Only neutrinos can go faster than the speed of light.

In a vacuum, which form of electromagnetic radiation travels slowest?

What are the three possible outcomes of stellar evolution? Describe each possibility, differentiating their means of formation and their subsequent properties. Which stars on the Main Sequence are thought to end up in each of these forms?

The Night Sky

Light and Telescopes

The Solar System

Earth and Its Moon

The Eight Planets

Small Bodies in the Solar System

Formation of Planetary Systems

The Sun

Measuring the Stars

Star Formation and Evolution

Stellar Explosions

The Milky Way Galaxy

Galaxies

Cosmology and the Universe

Filters