A thermodynamic cycle operates between hot and cold reservoirs at 1120 K and 540 K, respectively, while receiving energy via heat transfer from the hot reservoir at a rate of 1620 kW. The cycle discharges energy heat transfer to the cold reservoir, and develops a power at a rate of (a) 1000 kW, (b) 750 kW, (c) 0 kW. For each case, use the appropriate equation of a time-rate basis to determine whether the cycle operates reversibly, operates irreversibly, or is impossible. (sketch)