Homework #17, complete by Wednesday, Nov 4

0. Review 11.X.20-24 and check answers in book.

1. WebAssign HW 17
(Hint for first question: At standard temperature and pressure, one mole of any gas has a volume of 22.4 liters.)

ON PAPER:

2. 11.P.53
Hint: note that the angular momentum of the molecule is quantized such that L = l hbar, where l = 0, 1, 2, 3, ... and hbar = 1.05 X 10-34 J-s. Substitute this form in the rotational kinetic energy equation on pg. 404 and determine the moment-of-inertia by considering the description of the molecule.

3. In 1965, microwave radiation peaking at a wavelength of 0.107 cm was discovered coming from all directions from space. The presence of this radiation had been predicted by Ralph Alpher (at Union College from 1987-2004!) and Bob Hermann in 1948, who predicted that the hot Big Bang start of the Universe would leave behind a background remnant radiation. Due to the expansion of the Universe, the radiation has been redshifted to its current wavelength. To what temperature does the current wavelength correspond? This then is the temperature of space!

4. If you were to walk briefly in space without a spacesuit while far from the Sun (as an astronaut does in the classic 1968 movie 2001: A Space Odyssey ), you would feel the cold of space: while you radiated energy, you would absorb almost none from your environment. (a) At what rate would you lose energy, assuming that the T of space is 2.7 K? (b) How much energy would you lose in 30 s? Assume that your emissivity is 0.90 and estimate other data needed in the calculations.

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Last updated November 1, 2009