Universe: Stars And Galaxies
Universe: Stars And Galaxies
6th Edition
ISBN: 9781319115098
Author: Roger Freedman, Robert Geller, William J. Kaufmann
Publisher: W. H. Freeman
bartleby

Concept explainers

Question
Book Icon
Chapter 25, Problem 41Q
To determine

(a)

The critical density of matter in the universe.

Expert Solution
Check Mark

Answer to Problem 41Q

The critical density of matter in the universe is 4.699×1038kg/m3.

Explanation of Solution

Given:

The Hubble constant is, H1=50km/sMpc.

Formula used:

The critical density of matter in the universe is given by,

ρc=3H28πG

Calculation:

The gravitational constant is, G=6.67×1011m3/kgs2

The critical density of matter in the universe is calculated as,

ρc=3H28πG=3 ( 50 kmMpc/ sMpc )28π( 6.67× 10 11 m 3 / kg s 2 )=3 ( 50 km/ sMpc )2 ( 1Mpc 3.0856× 10 13 Mkm )28π( 6.67× 10 11 m 3 / kg s 2 )=3 ( 50 km/ sMpc )2 ( 1Mpc 3.0856× 10 13 Mkm( 10 6 km 1Mkm ) )2( 167.63 m 3 / kg s 2 )

Solve further,

ρc=3 ( 16.20× 10 19 s 1 )2( 167.63 m 3 / kg s 2 )=787.738× 10 38s 2( 167.63 m 3 / kg s 2 )=4.699×1038kg/m3

Conclusion:

The critical density of matter in the universe is 4.699×1038kg/m3.

To determine

(b)

The critical density of matter in the universe.

Expert Solution
Check Mark

Answer to Problem 41Q

The critical density of matter in the universe is 6.266×1038kg/m3.

Explanation of Solution

Given:

The Hubble constant is, H1=100km/sMpc.

Calculation:

The critical density of matter in the universe is calculated as,

ρc=3H28πG=3 ( 100 kmMpc/ sMpc )28π( 6.67× 10 11 m 3 / kg s 2 )=3 ( 100 km/ sMpc )2 ( 1Mpc 3.0856× 10 13 Mkm )28π( 6.67× 10 11 m 3 / kg s 2 )=3 ( 100 km/ sMpc )2 ( 1Mpc 3.0856× 10 13 Mkm( 10 6 km 1Mkm ) )2( 167.63 m 3 / kg s 2 )

Solve further,

ρc=3 ( 32.40× 10 19 s 1 )2( 167.63 m 3 / kg s 2 )=1050.317× 10 38s 2( 167.63 m 3 / kg s 2 )=6.266×1038kg/m3

Conclusion:

The critical density of matter in the universe is 6.266×1038kg/m3.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
Please don't use Chatgpt will upvote and give handwritten
5. An object moves in a horizontal plane with constant speed on the path shown. At which marked point is the magnitude of its acceleration greatest? A B Ꭰ E C
No chatgpt pls will upvote
Knowledge Booster
Background pattern image
Physics
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Text book image
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning
Text book image
Astronomy
Physics
ISBN:9781938168284
Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher:OpenStax
Text book image
Modern Physics
Physics
ISBN:9781111794378
Author:Raymond A. Serway, Clement J. Moses, Curt A. Moyer
Publisher:Cengage Learning
Text book image
Foundations of Astronomy (MindTap Course List)
Physics
ISBN:9781337399920
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Text book image
Stars and Galaxies
Physics
ISBN:9781305120785
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning