College Physics (10th Edition)
10th Edition
ISBN: 9780321902788
Author: Hugh D. Young, Philip W. Adams, Raymond Joseph Chastain
Publisher: PEARSON
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Chapter 30, Problem 49P
(a)
To determine
An expression for the critical density of the universe in the number of H atoms per cubic meter assuming that the whole universe is only hydrogen.
(b)
To determine
The average number of atoms in a room of dimension
(c)
To determine
Compare the number of atoms calculated in section (b) with the practical number of atoms generally found in a room.
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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
Scientists are conducting an experiment to determine if their hypothesis that a certain constant in the universe is 1.65. the uncertainties in the experiment result in a relative uncertainty of no more than 2%. After several experimental trials, the scientists obtained an average value of 1.7 for the constant. What can be said about the scientists hypothesis? Hint calculate the percent error and compare it to the relative uncertainty.
Suppose you are designing a proton decay experiment and you can detect 50 percent of the proton decays in a tank of water. (a) How many kilograms of water would you need to see one decay per month, assuming a lifetime of 1031 y ?
(b) How many cubic meters of water is this?
(c) If the actual lifetime is 1033 y , how long would you have to wait on an average to see a single proton decay?
Chapter 30 Solutions
College Physics (10th Edition)
Ch. 30 - Prob. 1CQCh. 30 - Prob. 2CQCh. 30 - True or false? During one half-life, the mass of a...Ch. 30 - Changing the temperature of atoms affects their...Ch. 30 - Prob. 5CQCh. 30 - Prob. 6CQCh. 30 - Prob. 7CQCh. 30 - Prob. 8CQCh. 30 - Prob. 9CQCh. 30 - Prob. 10CQ
Ch. 30 - Prob. 11CQCh. 30 - Prob. 12CQCh. 30 - Prob. 3MCPCh. 30 - Prob. 4MCPCh. 30 - Prob. 5MCPCh. 30 - Prob. 6MCPCh. 30 - Prob. 7MCPCh. 30 - Prob. 8MCPCh. 30 - Prob. 9MCPCh. 30 - Prob. 10MCPCh. 30 - Prob. 11MCPCh. 30 - Prob. 12MCPCh. 30 - Prob. 1PCh. 30 - Prob. 2PCh. 30 - Prob. 3PCh. 30 - Prob. 4PCh. 30 - Prob. 5PCh. 30 - Prob. 6PCh. 30 - Prob. 7PCh. 30 - Prob. 8PCh. 30 - Prob. 9PCh. 30 - Prob. 10PCh. 30 - Prob. 11PCh. 30 - Prob. 12PCh. 30 - Prob. 13PCh. 30 - Prob. 14PCh. 30 - Calcium-47 is a emitter with a half-life of 4.5...Ch. 30 - Prob. 16PCh. 30 - Prob. 17PCh. 30 - Prob. 18PCh. 30 - Prob. 19PCh. 30 - Prob. 20PCh. 30 - Prob. 21PCh. 30 - Prob. 22PCh. 30 - Prob. 23PCh. 30 - Prob. 24PCh. 30 - Prob. 25PCh. 30 - Prob. 26PCh. 30 - Prob. 27PCh. 30 - Prob. 28PCh. 30 - Prob. 29PCh. 30 - Prob. 30PCh. 30 - Prob. 31PCh. 30 - Prob. 32PCh. 30 - Prob. 33PCh. 30 - Prob. 34PCh. 30 - Prob. 35PCh. 30 - Prob. 36PCh. 30 - Prob. 37PCh. 30 - Prob. 38PCh. 30 - Prob. 39PCh. 30 - Prob. 40PCh. 30 - Prob. 41PCh. 30 - Prob. 42PCh. 30 - Prob. 43PCh. 30 - Prob. 44PCh. 30 - Prob. 45PCh. 30 - Prob. 46PCh. 30 - Prob. 47PCh. 30 - Prob. 48PCh. 30 - Prob. 49PCh. 30 - The results of activity measurements on a...Ch. 30 - Prob. 51GPCh. 30 - Prob. 52GPCh. 30 - Prob. 53GPCh. 30 - Prob. 54GPCh. 30 - Prob. 55GPCh. 30 - Prob. 56GPCh. 30 - Prob. 57GPCh. 30 - Prob. 58GPCh. 30 - Prob. 59GPCh. 30 - The atomic mass of 2056Co is 55.934939 u, and the...Ch. 30 - Prob. 61GPCh. 30 - Prob. 62GPCh. 30 - Prob. 63GPCh. 30 - Prob. 64PPCh. 30 - Prob. 65PPCh. 30 - Prob. 66PPCh. 30 - Prob. 67PPCh. 30 - Prob. 68PPCh. 30 - Prob. 69PPCh. 30 - Prob. 70PPCh. 30 - Prob. 71PP
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