the third chapter we learned is second law of thermo dynamics and we used another reference book. in this chapter, we learned about the thermal energy reservoir whoch refer to a hypothetical body with relative large thermal energy capacity such as ocean or sun. we also teached about the first statement of the second law which proposed by kelvin planck. he stated that there must be a heat loss during the course of cycle. Dr aznizam also explained to us about heat engines, heat pump and rerigerator. each of this three mechanism is different in their function. for heat engines it is used deliver heat from high-temperature reservoir to low-temperature reservoir while heat pumps is vice versa. while refrigerator has the same function as heat pump.
for calculating efficiency and cooefficient of perfomance
efficiency can not be more than 1 while COP can be greater than 1