Question

.85-120 Thermodynamics Tutorial 3 Problem 1. An inventor claims to have invented 4 engines, each of which operates between constant-temperature reservoirs of 400 and 300 K. Consider the 1st and 2nd laws of thermodynamics to evaluate the engines. For each engine, state and explain why it does or doesn't violate the 1st and 2nd Laws of Thermo. 1st law hint: Think quantity of work. 2nd Law hint: Think process efficiency. Engine 1 2 3 4 QH (J) 200 500 600 100 QL (1) -175 -200 -200 -90 W(J) 40 400 400 10 Problem 2. A Carnot engine produces power at a rate of 500W. It operates between constant- temperature reservoirs at 100 °C and 60 °C. Calculate the rate at which energy A) is taken in by the engine as heat; B) is exhausted by the engine as heat. Problem 3. The motor in a refrigerator requires power at a rate of 200W. The freezer compartment is at 270K and the outside air is at 300K. Assume that the refrigerator is ideal, in other words, it is a Carnot refrigerator. Calculate the maximum amount of energy that can be extracted as heat from the freezing compartment in 10 minutes. Problem 4. A 0.600 kg sample of water exists initially as ice at -20 °C. Calculate the change in entropy of the sample if its temperature is increased to 40 °C. Assume no thermal expansion for ice or water. ICE: C = 2220 J/(kg K) L: = 333 kJ/kg WATER = C = 4187 J/(kg-K) Problem 5. For 1 mole of a monoatomic ideal gas taken through the cycle below, where V, = 4V. A) calculate the numerical value of the ratio W/p.V, as the gas goes from a to c along abc; B) calculate AEnt/p.V. in going from b to c; C) calculate AEnt in going through 1 full cycle; D) calculate AS in going from b toc E) calculate AS in going through 1 full cycle

Answer 1

As you have posted multiple questions in a single window so I should provide solution for first question only as per the HOMEWORKLIB RULES but still I am providing solution for initial 2 questions so that it will help you a little bit more.

Please find the attached solution.