1. Energy from the air was tranferred Into the ballon as heat. The ballon did work on the book.
2. Due to the second law of Thermodynamics, the efficiency equals the net work done divided by the energy Added as heat. … because the remaining heat removed divided by the heat added Will be always less than 1.
3. The water freezes because there is an Exchange of heat in the system that transfer coldness from the refrigerator Engine to the water
4. There is no change in the system’s Internal energy. AU=0 bc it remains constant where the variation is 0.
5. The final and initial values of Internal energy are the same and the change in IE is 0. AU=0, according to the Law of conservation the net work and net heat are equal.