Last visit was: 26 Apr 2024, 02:43 It is currently 26 Apr 2024, 02:43

Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
User avatar
Director
Director
Joined: 03 Apr 2007
Posts: 632
Own Kudos [?]: 4800 [1]
Given Kudos: 10
Send PM
avatar
Manager
Manager
Joined: 23 May 2006
Posts: 143
Own Kudos [?]: 1129 [0]
Given Kudos: 0
Send PM
User avatar
Senior Manager
Senior Manager
Joined: 10 Sep 2007
Posts: 458
Own Kudos [?]: 938 [0]
Given Kudos: 0
 Q50  V34
Send PM
Senior Manager
Senior Manager
Joined: 24 Aug 2009
Posts: 388
Own Kudos [?]: 2261 [0]
Given Kudos: 276
Concentration: Finance
Schools:Harvard, Columbia, Stern, Booth, LSB,
Send PM
Re: Astronomers theorize that a black hole forms when a massive [#permalink]
Complete discussion at the below mentioned link
astronomers-theorize-that-a-black-hole-forms-when-a-massive-147401.html#p1183399



astronomers-theorize-that-a-black-hole-forms-when-a-massive-147401.html#p1183399
goalsnr wrote:
Astronomers theorize that a black
hole forms when a massive object
shrinks catastrophically under its own
Line gravity, leaving only a gravitational
(5)field so strong that nothing escapes it.
Astronomers must infer the existence
of black holes, which are invisible,
from their gravitational influence on
the visible bodies surrounding them.
(10)For example, observations indicate
that gas clouds in galaxy M87 are
whirling unusually fast about the galaxy’s
center. Most astronomers
believe that the large concentration
(15)of mass at the galaxy’s center is a
black hole whose gravity is causing
the gas to whirl. A few skeptics have
argued that the concentration of mass
necessary to explain the speed of the
(20)whirling gas is not necessarily a black
hole: the concentration in M87 might
be a cluster of a billion or so dim stars.
The same hypothesis might have
been applied to the galaxy NGC 4258,
(25)but the notion of such a cluster’s
existing in NGC 4258 was severely
undermined when astronomers measured
the speed of a ring of dust and
gas rotating close to the galaxy’s
(30)center. From its speed, they calculated
that the core’s density is more
than 40 times the density estimated
for any other galaxy. If the center of
NGC 4258 were a star cluster, the
(35)stars would be so closely spaced
that collisions between individual
stars would have long ago torn the
cluster apart.
--------------------------------------------------------------------------------
Q10:
The skeptics mentioned in the first paragraph would be most likely to agree with the
astronomers mentioned in line 13 about which of the following statements concerning
the galaxy M87?
A. The speed of the gas whirling around the center of M87 is caused by a dense
object that is not a black hole.
B. The concentration of mass at the center of M87 is probably a large cluster of
dim stars.
C. The presence of a black hole at the center of M87 is the most likely
explanation for the speed of the gas whirling about the galaxy’s core.
D. The speed of the gas whirling around the center of M87 is caused by a large
concentration of mass at the core of M87.
E. The gravitational influence of a star cluster would not be strong enough to
account for the speed of the gas whirling around the core of M87.
MBA Section Director
Joined: 22 May 2017
Affiliations: GMATClub
Posts: 12745
Own Kudos [?]: 8832 [0]
Given Kudos: 3034
GRE 1: Q168 V154
GPA: 3.4
WE:Engineering (Education)
Send PM
Re: Astronomers theorize that a black hole forms when a massive [#permalink]
Expert Reply
Discussed here astronomers-theorize-that-a-black-hole-forms-when-a-massive-object-147401.html?fl=similar

Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Reading Comprehension (RC) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
GMAT Club Bot
Re: Astronomers theorize that a black hole forms when a massive [#permalink]
Moderators:
GMAT Club Verbal Expert
6921 posts
GMAT Club Verbal Expert
238 posts
GRE Forum Moderator
13961 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne