Question 1

The densest state of matter found in nature occurs inside a white dwarf star.

Accepted Answer

A) True 
 B)False

Question 2

Type I and Type II supernovae are approximately equal in luminosity.

Accepted Answer

A) True 
 B)False

Question 3

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 4

Einstein's special theory of relativity implies that if a person standing at the front of a train traveling at 0.1 km/s shines a flashlight out in front of the train,the emitted photons will travel at a speed of 300,000.1 km/s.

Accepted Answer

A) True 
 B)False

Question 5

Special relativity says that moving clocks run slower.

Accepted Answer

A) True 
 B)False

Question 6

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 7

A Cepheid star varies in luminosity because

Accepted Answer

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

Question 8

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

Accepted Answer

They have very strong winds be

Question 9

What would happen if mass were continually added to a   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 10

We can determine the age of a star cluster by measuring the color of the reddest red giant stars in the cluster.

Accepted Answer

A) True 
 B)False

Question 11

Essentially all the elements heavier than iron in our galaxy were formed

Accepted Answer

A)  by supernovae. 
B)  during the formation of black holes. 
C)  by fusion in the cores of the most massive main-sequence stars. 
D)  during the formation of planetary nebulae. 
A)  by supernovae. 
B)  during the formation of black holes. 
C)  by fusion in the cores of the most massive main-sequence stars. 
D)  during the formation of planetary nebulae.

Question 12

Suppose we discovered radio signals coming from the star Alpha Centauri,whose distance is 4.4 light-years from us,and we sent a crew in a spacecraft to visit it.If the spacecraft used revolutionary technology allowing it to travel at a speed of 0.5 c,how long would it take the spacecraft to get to Alpha Centauri,and how long a time would the astronauts say passed during the trip? (Ignore the time it would take to accelerate the spacecraft to reach a velocity of 0.5 c.)

Accepted Answer

Traveling at a speed of 0.5 c,the time i

Question 13

Black holes that are stellar remnants can be found by searching for

Accepted Answer

A)  dark regions at the centers of galaxies. 
B)  variable X-ray sources. 
C)  extremely luminous infrared objects. 
D)  objects that emit very faint radio emission. 
A)  dark regions at the centers of galaxies. 
B)  variable X-ray sources. 
C)  extremely luminous infrared objects. 
D)  objects that emit very faint radio emission.

Question 14

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

Accepted Answer

(1)Photodisintegration uses up the therm

Question 15

Fusion reactions that create chemical elements heavier than oxygen require energy input,thus these reactions cannot provide a star with power.

Accepted Answer

A) True 
 B)False

Question 16

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 17

What characteristic of a star cluster is used to determine its age?

Accepted Answer

A)  The chemical composition of stars in the cluster 
B)  The luminosity of the faintest stars in the cluster 
C)  The color of the main sequence turnoff in the cluster 
D)  The total number of stars in the cluster 
A)  The chemical composition of stars in the cluster 
B)  The luminosity of the faintest stars in the cluster 
C)  The color of the main sequence turnoff in the cluster 
D)  The total number of stars in the cluster

Question 18

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 19

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

Accepted Answer

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

Question 20

Most of the uranium   found on the Earth was formed in Type II supernova explosions.

Accepted Answer

A) True 
 B)False

Exam 17: Live Fast,die Younghigh-Mass Stellar Evolution

The densest state of matter found in nature occurs inside a white dwarf star.

Type I and Type II supernovae are approximately equal in luminosity.

Hawking radiation is emitted by a black hole when

Einstein's special theory of relativity implies that if a person standing at the front of a train traveling at 0.1 km/s shines a flashlight out in front of the train,the emitted photons will travel at a speed of 300,000.1 km/s.

Special relativity says that moving clocks run slower.

Gravitational lensing occurs when __________ distorts the fabric of spacetime.

A Cepheid star varies in luminosity because

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

What would happen if mass were continually added to a neutron star?

We can determine the age of a star cluster by measuring the color of the reddest red giant stars in the cluster.

Essentially all the elements heavier than iron in our galaxy were formed

Black holes that are stellar remnants can be found by searching for

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

Fusion reactions that create chemical elements heavier than oxygen require energy input,thus these reactions cannot provide a star with power.

The equivalence principle says that

What characteristic of a star cluster is used to determine its age?

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.

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

Most of the uranium found on the Earth was formed in Type II supernova explosions.

Why Learn Astronomy

Patterns in the Skymotions of Earth

Gravity and Orbitsa Celestial Ballet

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquidthe Giant Planets

Gravity Is More Than Keplers Laws

Planetary Adornmentsmoons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

A Run-Of-The-Mill G-Type Starour Sun

Star Formation and the Interstellar Medium

Stars in the Slow Lanelow-Mass Stellar Evolution

Our Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

The Origin of Structure

Life

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