UNIVERSE (LOOSELEAF):STARS+GALAXIES
6th Edition
ISBN: 9781319115043
Author: Freedman
Publisher: MAC HIGHER
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Chapter 25, Problem 37Q
To determine
The critical density of the universe and importance of critical density to the cosmologists.
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Suppose that you have a flat universe that has matter and dark energy with wd = -2/3 & Ωd,0 =0.7
At the time when light with z = 1 was emitted from a distant galaxy what was the ratio Ɛd /Ɛm ?
I asked the following question and was given the attached solution:
Suppose that the universe were full of spherical objects, each of mass m and radius r . If the objects were distributed uniformly throughout the universe, what number density (#/m3) of spherical objects would be required to make the density equal to the critical density of our Universe?
Values:
m = 4 kg
r = 0.0407 m
Answer must be in scientific notation and include zero decimal places (1 sig fig --- e.g., 1234 should be written as 1*10^3)
I don't follow the work and I got the wrong answer, so please help and show your work as I do not follow along easily
thanks
Chapter 25 Solutions
UNIVERSE (LOOSELEAF):STARS+GALAXIES
Ch. 25 - Prob. 1QCh. 25 - Prob. 2QCh. 25 - Prob. 3QCh. 25 - Prob. 4QCh. 25 - Prob. 5QCh. 25 - Prob. 6QCh. 25 - Prob. 7QCh. 25 - Prob. 8QCh. 25 - Prob. 9QCh. 25 - Prob. 10Q
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