An air standard cycle is executed in a closed system with 0.005 kg of air, and it consists of the following three processes: (1) Isentropic compression from 200 kPa, 30oC to 2 MPa, (2) p = constant during heat addition in the amount of 2 kJ, (3) p = c1v + c2 heat rejection to initial state. Calculate
(a) The heat rejected, and
(b) The thermal efficiency (ηth). Assume constant specific heats at room temperature.