1. Clicker question 1 Can you make it to the midterms on the evenings of Friday, Oct. 3 and Friday, Nov. 7, from 7:00-8:15 PM? A.Yes B.No

2. Clicker question 2 Would having the midterms on another evening during the week work better for you? A.Yes, Monday evenings work better B.Yes, Wednesday evenings work better C.No, Friday evenings are fine D.I can’t make it to evening exams at all

3. Clicker question 3 Consider two volumes of gas (not necessarily the same gas) separated by a moveable (but impermeable) glass barrier. Which quantities are the same after equilibration? A.Temperature B.Temperature and pressure C.Temperature, pressure, and number density (N/V) D.Temperature and volume E.Temperature, pressure, and volume Gas 1Gas 2 Glass wall T 1, P 1, N 1, V 1 T 2, P 2, N 2, V 2 N 1, N 2 constant V 1 + V 2 = V constant

4. Clicker question 4 Suppose you double the number of molecules in an ideal gas, keeping the average kinetic energy per molecule and volume V fixed. What changes? A.Temperature only B.Pressure only C.Temperature and density (N/V) D.Pressure and density E.Temperature, pressure, and density

5. Clicker question 5 Suppose you double the average kinetic energy per molecule in an ideal gas, keeping N and V fixed. What changes? A.Temperature only B.Pressure only C.Both temperature and pressure

6. Clicker question 6 An ideal gas traverses the thermodynamic pathway in the P-V plane shown above. In process A, the internal energy U of the gas A.Increases B.Decreases C.Stays the same

7. Clicker question 7 An ideal gas traverses the thermodynamic pathway in the P-V plane shown above. In process A, the work W done on the gas is A.Positive B.Negative C.Zero

8. Clicker question 8 An ideal gas traverses the thermodynamic pathway in the P-V plane shown above. In process A, the heat Q flowing into the gas is A.Positive B.Negative C.Zero

9. Clicker question 9 An ideal gas expands from volume V 0 to volume 2V 0 at constant pressure P 0 as shown in the P-V diagram above. In this process the temperature T of the gas A.Stays the same B.Decreases by a factor of two C.Increases by a factor of two

10. Clicker question 10 The pressure of an ideal gas is reduced from pressure 2P 0 to pressure P 0 at constant volume V 0 as shown in the P-V diagram above. In this process the internal energy U of the gas A.Stays the same B.Decreases by a factor of two C.Increases by a factor of two

11. Clicker question 11 A monatomic ideal gas (Gas 1) is placed in thermal contact with a diatomic ideal gas (Gas 2). The two gases have the same number of molecules N and volume V, but are initially at different temperatures (T 2 > T 1 ). After some time the two gases come to thermal equilibrium (T 1 = T 2 = T) with internal energies U 1 and U 2. In thermal equilibrium A. U 1 = U 2 B. U 1 > U 2 C. U 1 < U 2

12. Clicker question 12 The game of Yahtzee involves rolling 5 standard six-sided dice, where each die can have an integer value ranging from 1 to 6. How many distinct macrostates (distinct sum total values of the 5 dice) are there? A.5 B.30 C.26 D.5 6 E.6 5

13. Clicker question 13 The game of Yahtzee involves rolling 5 standard six-sided dice, where each die can have an integer value ranging from 1 to 6. How many distinct microstates (distinct combinations of dice) are there? A.5 B.30 C.26 D.5 6 E.6 5

14. Clicker question 14 The game of Yahtzee involves rolling 5 standard six-sided dice, where each die can have an integer value ranging from 1 to 6. What is the multiplicity (number of distinct microstates) of the macrostate with a sum total value of dice equal to 28? A.5 B.6 C.10 D.15 E.30

15. Clicker question 15 10 molecules undergoing random thermal motion are confined to a box of volume V. What’s the approximate probability of finding 7 of the molecules in the right-hand side of the box (of volume V/2) at any given time? A.1 B.10 -1 C.10 -3 D.10 -5 E.10 -7

16. Clicker question 16 Suppose two systems, A and B, are brought into thermal contact. System A has Ω A microstates, and system B has Ω B microstates. How many microstates does the combined system have? A. B. C. D. E.

17. Clicker question 17 What is 1000!, approximately? Hint: assume that 10 = e 2 for the purpose of doing this problem. A. 10 20 B. 10 250 C. 10 1000 D. 10 2500 E. 10 5000

18. Clicker question 18 I’m thinking of a number between 0 and 1,000,000. How many yes/no questions do you need to ask me to determine the number? A. 7 B. 20 C. 100 D. 1,000 E. 1,000,000

19. Clicker question 19 Two classical, monatomic ideal gases, A and B, each containing N atoms and occupying a volume V, are placed in thermal equilibrium, so that they share a total internal energy U, i.e. U = U A + U B. If N = 10 24, the fraction of macrostates that occur with non-negligible probability is on the order of: A. 10 -2 B. 10 -4 C. 10 -6 D. 10 -12 E. 10 -24

20. Clicker question 20 Would it be helpful for me to have additional office hours tomorrow (Thursday afternoon)? A.No, I’ve got everything under control and don’t need the help B.No, I’m busy all afternoon, so this wouldn’t help me C.Yes, I could use some help

21. Clicker question 21 The entropy S of a system varies with energy U as shown in the figure above. How does the temperature at point 1 compare to the temperature at point 2? A. T 1 > T 2 B. T 1 < T 2 C. T 1 = T 2 D. Not enough information given