1. How much work is done by the gas in the cycle shown? A] 0 B] p 0 V 0 C] 2p 0 V 0 D] -2p 0 V 0 E] 4 p 0 V 0 How much total heat is added to the gas in the cycle shown? If “negative heat” is added to the gas, this means more heat is expelled from the gas than taken in. (The difference is the work done on the gas.)

2. In one (ccw) Carnot cycle shown, the work done by the gas is: A] + B] - C] 0

3. A] 1-2 B] 2-3 C] 3-4 D] 4-1 E] none Work < 0, so Q < 0. Along which paths is heat expelled from the gas?

4. Heat is expelled from the gas during isothermal compression 3- 4. Heat is added to the gas during isothermal expansion 1-2. More heat is expelled than added. The net effect is to take heat from a cold reservoir, and add it to a hot reservoir (along with some extra heat from the work done on the gas.) This is a fridge!

5. The laws of mechanics (and E&M, etc.) are time-reversal invariant. So how come this looks funny? http://www.youtube.com/watch?v=mGZjCUKowIs