Problem_of_the_Week_&acirc;€“_13

# Problem_of_the_Week_&acirc;€“_13 - a Which...

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Problem of the Week – 13 The diagrams below are potential energy diagrams for microscopic oscillators (masses and springs). The energy axis is drawn to the same scale in the two diagrams, as is the displacement axis. One of the diagrams represents the first few energy states for motion in the x-direction of an atom in a block of copper, and the other represents the first few energy states for motion in the x-direction of an atom in a block of gold. The mass of a mole of copper is 64 g, and the interatomic spring stiffness for Cu is 28 N/m. The mass of a mole of gold is 197 g, and the interatomic spring stiffness is 20 N/m. The
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Unformatted text preview: a) Which diagram (A or B) represents copper, and which represents gold? Give two reasons justifying your answer. b) Two blocks of metal, one containing a mole of copper atoms, the other containing a mole of gold atoms, are initially at a very low temperature, close to 0 K. Suppose that one joule of energy were added to each block. Now which block has the greater entropy? Explain your reasoning clearly. Do not skip any steps in reasoning – be explicit about each inference. c) Which block now has the higher temperature? Explain. Ground state E E 1 E 2 E 3 E 4 Ground state E E 5 E 6 E 7 E 1 E 2 E 3 E 4 A B...
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## This note was uploaded on 12/07/2011 for the course PHYS 172 taught by Professor ? during the Fall '08 term at Purdue.

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