Briefly describe the four possible expansion patterns of the universe
What will be an ideal response?
1. Recollapsing universe: the density of the universe is greater than critical. Gravity will eventually reverse the expansion, resulting in a "Big Crunch."
2. Critical universe: the density of the universe is equal to the critical density. Gravity just balances the expansion which slows increasingly down toward zero as time progresses.
3. Coasting universe: the density of the universe is less than the critical density. The expansion overwhelms the attractive force of gravity and the universe expands without limit.
4. Accelerating universe: a mysterious repulsive force that acts against gravity on large scales causes the universe to expand with ever-increasing speed.
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Answer the following statement(s) true (T) or false (F)
1. The quantity Z in the expression 
depends on the temperature T of the reservoir.
2. At a sufficiently high temperature, an oscillator in an Einstein solid is more likely to have one unit of energy than no energy at all.
The fundamental frequency of a violin string is 440 hertz. The frequency of its second harmonic is
A) 220 hertz. B) 440 hertz. C) 880 hertz. D) none of the above
The radiation given off by the nucleus of an atom is called
a. a microwave. b. a gamma ray. c. an X-ray. d. any of these.
A distinctive feature of quarks is that they
A) are always observed singly, since they do not readily interact with other particles. B) have zero charge. C) have zero rest mass. D) have fractional electric charge.