A150 mm long normalized 1045 steel shaft is turned down from a diameter of 100 mm to 90 mm in a single pass. the side cutting edge angle σ is 0°, the cutting speed v is 135 m/min, and the feed per revolution fr is 0.22 mm. determine (a) the chip area a [mm2], (b) the material removal rate q [cm3/min], (c) the tangential component of the cutting force ft [kn], (d) the power needed to drive the turning operation p [kw], and (e) the machining time t [min].

Air enters a gas turbine with two stages of compression and two stages of expansion at 100 kpa and 17°c. this system uses a regenerator as well as reheating and intercooling – the intercooler returns the air to the inlet temperature. the pressure ratio across each compressor is 4 ; 300 kj/kg of heat are added to the air in each combustion chamber; and the regenerator operates perfectly while increasing the temperature of the cold air by 20°c. determine the system’s thermal efficiency. assume isentropic operations for all compressor and the turbine stages and use constant specific heats at room temperature. (0.378)