EBK INQUIRY INTO PHYSICS
8th Edition
ISBN: 8220103599450
Author: Ostdiek
Publisher: Cengage Learning US
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Chapter 12, Problem 11Q
To determine
The reason due to which it is reasonable to expect that the rate at which the universe is expanding, will decrease with time. Also state whether the observations related to motions of remote galaxies support this position or not. If not, then determine the implications suggested by the observations relating to change in the rate of expansion.
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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)
esc
a) 10 points) Gravitational Time Dilation. The escape velocity from the surface (radius r) of a star or
planet of mass M is given by the formula v = (2GM/r). Use this expression to write the time-dilation
fraction, At/t, in terms of the ratio of vesc to the speed of light, c. Hint: This is just a simple exercise in
substitution.
5.98 x 1024 kg
b) (10 points) Extra Lifetime on the Surface of Earth. The Earth has mass MEarth
and radius REarth 6.38 x 10 m. What is the fractional time-dilation (At/t) for someone on the Earth's
surface? How much longer (At) is a typical lifetime on the surface of Earth, compared to someone in deep
space, far away from Earth? Assume a typical human life span of t = 80 years.
I
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 12 Solutions
EBK INQUIRY INTO PHYSICS
Ch. 12 - Prob. 1AACh. 12 - Prob. 2AACh. 12 - Prob. 1PIPCh. 12 - Prob. 1MIOCh. 12 - Prob. 2MIOCh. 12 - Prob. 1QCh. 12 - Prob. 2QCh. 12 - Prob. 3QCh. 12 - Prob. 4QCh. 12 - Prob. 5Q
Ch. 12 - Prob. 6QCh. 12 - Prob. 7QCh. 12 - Prob. 8QCh. 12 - Prob. 9QCh. 12 - (Indicates a review question, which means it...Ch. 12 - Prob. 11QCh. 12 - Prob. 12QCh. 12 - (Indicates a review question, which means it...Ch. 12 - Prob. 14QCh. 12 - Prob. 15QCh. 12 - Prob. 16QCh. 12 - Prob. 17QCh. 12 - Prob. 18QCh. 12 - Prob. 19QCh. 12 - Prob. 20QCh. 12 - Prob. 21QCh. 12 - Prob. 22QCh. 12 - Prob. 23QCh. 12 - Prob. 24QCh. 12 - Prob. 25QCh. 12 - Prob. 26QCh. 12 - Prob. 27QCh. 12 - Prob. 28QCh. 12 - Prob. 29QCh. 12 - Prob. 30QCh. 12 - Prob. 31QCh. 12 - Prob. 32QCh. 12 - Prob. 33QCh. 12 - Prob. 34QCh. 12 - Prob. 35QCh. 12 - Prob. 36QCh. 12 - Prob. 37QCh. 12 - Prob. 38QCh. 12 - Prob. 39QCh. 12 - Prob. 40QCh. 12 - Prob. 41QCh. 12 - Prob. 42QCh. 12 - Prob. 43QCh. 12 - Prob. 44QCh. 12 - Prob. 1PCh. 12 - How fast would a muon have to be traveling...Ch. 12 - The lifetime of a free neutron is 886 s. If a...Ch. 12 - Prob. 4PCh. 12 - The formula for length contraction gives the...Ch. 12 - Prob. 6PCh. 12 - Prob. 7PCh. 12 - Prob. 8PCh. 12 - Prob. 9PCh. 12 - . In a particular beam of protons, each particle...Ch. 12 - . A particle of rest energy 140 MeV moves at a...Ch. 12 - . If the relativistic kinetic energy of a particle...Ch. 12 - Prob. 13PCh. 12 - Prob. 14PCh. 12 - Prob. 15PCh. 12 - . How many years would you have to wait to observe...Ch. 12 - Prob. 17PCh. 12 - Prob. 18PCh. 12 - . A compact neutron star has a mass of kg (about...Ch. 12 - Prob. 20PCh. 12 - Prob. 21PCh. 12 - Prob. 22PCh. 12 - Prob. 23PCh. 12 - Prob. 24PCh. 12 - Prob. 25PCh. 12 - Prob. 26PCh. 12 - Prob. 27PCh. 12 - Prob. 28PCh. 12 - Prob. 29PCh. 12 - Prob. 30PCh. 12 - Prob. 31PCh. 12 - . If the average lifetime of a proton was 1033...Ch. 12 - Prob. 1CCh. 12 - Prob. 2CCh. 12 - Prob. 3CCh. 12 - Prob. 4CCh. 12 - Prob. 5CCh. 12 - Prob. 6CCh. 12 - Prob. 7CCh. 12 - Prob. 8CCh. 12 - Prob. 9CCh. 12 - Prob. 10C
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