Description
1. Is a hydroelectric power plant a heat engine? How about a windmill? A race car engine? A steam locomotive?
2. A certain cyclical heat engine performs 3000 J of work in each cycle and exhausts 27000 J of thermal energy in each cycle.
a. What must the thermal energy input be for each cycle of the engine?
b. What is the efficiency of the engine?
c. What fraction of the input energy becomes thermal energy exhaust?
3.-a.- What has higher entropy: a large box containing a balloon filled with helium and a lot of air, or, the same box after the helium is released from the balloon and distributes itself throughout the box, mixing in with the air present.
b.- Explain why if you release the helium out of a helium birthday balloon you will not be able to observe the helium spontaneously go back into the balloon.
4.- Someone is preparing “sangria” for a party. This requires the mixing of orange juice with red wine.
If we consider the system of interest to be the liquids originally in the bottles of orange juice, and red wine.
a.- What happens with the entropy of the system as a result of the preparation of the sangria?
b.- If the sangria is poured back into the empty bottles of red wine and orange juice, do you expect that one bottle will end up only having orange juice and the other only having red wine?
Why or why not?