Oxygen is contained in a piston-cylinder system initially at a temperature of 40 °c and a pressure of 150 kpa. the piston is 1 m in diameter and initially 20 cm above the base of the cylinder. heat is added at constant pressure until the piston has moved 30 cm. a)-what is the mass of gas contained in the piston, in kg? b)-what is the final temperature of the system, in k? c)-using the table of properties of oxygen as an ideal gas, calculate the heat added to the system per unit mass, in kj/kg. d)-repeat this calculation assuming that the specific heat as a function of temperature is linear over this range of temperatures (i. e., assuming that the change in temperature is "small"). e)-repeat this calculation without this assumption (i. e., direct integration of empirical relation) f)- discuss the variations in your results across the methods (note: all methods will give close to the same answer, if calculated correctly). g)-using any of the methods that you conclude to be accurate, calculate the change in the specific internal energy of the system, in kj/kg.