Nitrogen in a horizontal piston-cylinder assembly expands from an initial volume of 0.10 m3 to a final volume of 0.5 m3 as the gas is heated for 5 minutes by an electrical resistance heater consuming 1 kW of electric power. If the pressure remains constant at 150 kPa, and 70 kJ of heat is lost from the cylinder during the expansion process, determine
(a) the boundary work transfer (include sign),
(b) electrical work transfer (include sign), and
(c) the net energy transfer (absolute value) into the system through heat and work.[Solutions]