(Originais Teachy 2023) - Question Medium of Physics

A system with an ideal gas undergoes a thermodynamic cycle composed of three processes: (1) an isothermal expansion, in which the gas performs work on the surroundings; (2) an adiabatic compression, in which work is done on the gas and its temperature increases; and (3) an isothermal compression, in which the gas releases heat to the surroundings and returns to its initial state. For this thermodynamic cycle, answer the following items: (a) Describe the behavior of the gas's internal energy in each of the three processes. (b) Calculate the work done by the gas in the isothermal expansion process, considering that the temperature remains constant at 300 K, and the gas expands from an initial volume of 0.01 m³ to a final volume of 0.03 m³. The ideal gas constant (R) is equal to 8.31 J/mol.K and the amount of gas is 2 moles. (c) Knowing that the gas released 300 J of heat in the isothermal compression process and that the value of work in the adiabatic processes is half the value of the isothermal process, determine the efficiency of the cycle, that is, the ratio between the total work done by the gas and the total amount of heat absorbed throughout the cycle.