21st Century Astronomy
6th Edition
ISBN: 9780393428063
Author: Kay
Publisher: NORTON
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Chapter 22, Problem 36QP
(a)
To determine
The axis is linear or logarithmic.
(b)
To determine
The order of magnitude at which the density of the universe dropped.
(c)
To determine
The order of temperature at which it has dropped.
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Students have asked these similar questions
1. If a galaxy is 9.1 Mpc away from Earth and recedes at 511 km/s, what is H0 (in km/s/Mpc)?
2. What is the Hubble time (in yr)?
3. How old (in yr) would the universe be, assuming space-time is flat and the expansion of the universe has not been accelerating?
An astronomer observed the motions of some galaxies. Based on his observations, he made the following statements. Which one of them is most likely to be false? Take Hubble's constant to be 67 km/s/Mpc.
A. A galaxy observed to be moving away from us at a speed of 70 km/s is at a distance of about 1 Mpc from us.
B. A galaxy observed to be moving away from us at a speed of 700 km/s is at a distance of about 10 Mpc from us.
C. A galaxy observed to be moving away from us at a speed of 7000 km/s is at a distance of about 100 Mpc from us.
D. A galaxy observed to be moving away from us at a speed of 70000 km/s is at a distance of about 1 Gpc from us.
Is the answer D? Thank you!
If a galaxy is 9.0 Mpc away from Earth and recedes at 488 km/s, what is H0 (in km/s/Mpc)?
km/s/Mpc
What is the Hubble time (in yr)?
years
How old (in yr) would the universe be, assuming space-time is flat and the expansion of the universe has not been accelerating?
How would acceleration change your answer?
A.If the expansion of the Universe has been accelerating, the Universe could be substantially younger than the value entered above.
BIf the expansion of the Universe has been accelerating, the Universe could be substantially older than the value entered above.
Chapter 22 Solutions
21st Century Astronomy
Ch. 22.1 - Prob. 22.1CYUCh. 22.2 - Prob. 22.2CYUCh. 22.3 - Prob. 22.3CYUCh. 22.4 - Prob. 22.4CYUCh. 22.5 - Prob. 22.5CYUCh. 22 - Prob. 1QPCh. 22 - Prob. 2QPCh. 22 - Prob. 3QPCh. 22 - Prob. 4QPCh. 22 - Prob. 5QP
Ch. 22 - Prob. 6QPCh. 22 - Prob. 7QPCh. 22 - Prob. 8QPCh. 22 - Prob. 9QPCh. 22 - Prob. 10QPCh. 22 - Prob. 11QPCh. 22 - Prob. 12QPCh. 22 - Prob. 13QPCh. 22 - Prob. 14QPCh. 22 - Prob. 15QPCh. 22 - Prob. 16QPCh. 22 - Prob. 17QPCh. 22 - Prob. 18QPCh. 22 - Prob. 19QPCh. 22 - Prob. 20QPCh. 22 - Prob. 21QPCh. 22 - Prob. 22QPCh. 22 - Prob. 24QPCh. 22 - Prob. 28QPCh. 22 - Prob. 29QPCh. 22 - Prob. 31QPCh. 22 - Prob. 32QPCh. 22 - Prob. 33QPCh. 22 - Prob. 34QPCh. 22 - Prob. 35QPCh. 22 - Prob. 36QPCh. 22 - Prob. 37QPCh. 22 - Prob. 38QPCh. 22 - Prob. 39QPCh. 22 - Prob. 40QPCh. 22 - Prob. 41QPCh. 22 - Prob. 42QPCh. 22 - Prob. 43QPCh. 22 - Prob. 44QPCh. 22 - Prob. 45QP
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- What are the angular diameters of the following, as seen from Earth? a. The Sun, with radius R = Rsun = 7x10^5 km. b. Betelgeuse, with MV = -5.5 mag, mv = 0.8 mag, and R = 650Rsun. c. The galaxy M31, with R = 30 kpc at a distance D = 0.7Mpc. d. The Coma cluster of galaxies, with R = 3 Mpc at a distance D = 100 Mpc.arrow_forwardIf our universe is expanding, what are the implications for the separation between two stars within our galaxy? A. The two stars are moving farther apart. B. The two stars are moving closer together. C. The distance between the two stars is unaffected. D. The question is impossible to answer without more information.arrow_forwardIn 1998, it was announced that the expansion of the universe is accelerating. What does this imply from the perspective of the big bang? a. A force exists that we knew nothing about causes the expansion. b. The universe must be closed. c. The universe is finite. d. The amount of dark matter must be far less than the amount of normal matter. e. The universe must be infinitely old.arrow_forward
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