Question

A, B , D ,E PLEASE SOLVE THEM ( DETAILED SOLUTION + CLEAR HANDWRITING)

In this question, assume no changes in Ek or Ep (a) In one cycle of a heat engine: 70 J are input by working, 90 J are output by working, 100 J are input by heating, 80 J are output by heating. Write down which one of the following is true: (A) |Wnet-160 J (B) Iw.et-20 J (C) η-0.25 (b) For a fixed amount of gas, held in a cylinder by a piston, write down which one of the following is true (A) for an isothermal process: W-Q (B) for an adiabatic process: W 0 (C) for expansion at constant pressure: Q> 0 (D) for an isothermal process: Q 0 (E) for adiabatic expansion: Q<0 c) Gas in a heat engine undergoes a cycle involving three processes in the following order: 1: isothermal expansion 2: isobaric compression 3: adiabatic compression Sketch the cycle on a single P: V diagram, labelling each process (1, 2 and 3 respectively) and showing the direction of each process with an arrow. (d) Helium gas has cu-12.5 J mol-"K-1, n = 100 mol of helium gas ini- tially has volume 0.2 m3 and pressure 5 x 106 Pa. Find the energy transfer by heating if pressure increases by 50% due to an isochoric process. (You do not need to know n but I include it in case you use a different method) (e) 100 mol of gas initially has pressure 5 x 106 Pa, temperature 700 K. The gas then undergoes isobaric compression with final volume 0.05 m3. Find W for the gas.

Answer 1