For a few hundred thousand years after the Big Bang, atoms could not form. Electrons could not stay bound to protons or helium nuclei. However, eventually, atoms did combine when
A. there was enough angular momentum that protons and electrons acquired spins.
B. the universe had expanded and cooled sufficiently.
C. the theory of everything became active.
D. the curvature of spacetime increased by 50%.
Answer: B
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Answer the following statement true (T) or false (F)
The energy in the atmospheres of most of the jovian planets comes
A) almost entirely from their interiors. B) almost entirely from the Sun. C) both the Sun and their interiors, with both contributing significantly. D) tidal heating.
A stationary 1.67-kg object is struck by a stick. The object experiences a horizontal force given by F = at - bt2, where t is the time in milliseconds from the instant the stick first contacts the object
If a = 1500 N/(ms) and b = 20 N/(ms)2, what is the speed of the object just after it comes away from the stick at t = 2.74 ms? A) 3.3 m/s B) 22 m/s C) 3.7 m/s D) 25 m/s
Based on inventoried matter in the universe, including dark matter known to exist in galaxies and clusters, the actual density of the universe is what fraction of the critical density?
A) 1 percent B) 10 percent C) 26 percent D) 74 percent E) 100 percent