Methane is expanded in a sealed cylinder through a process in which 50 BTU of heat is added. The mass of the methane in the cylinder is 0.5 Ibm. Assume that the methane is an ideal gas. Initial State: T_1 = 60-degF V_1 := 0.58 ft^3 p_1:= 300.PSi Final State: T_2 = 264 degF V_2 := 0.7 ft^3 p_2:= 346 Psi Determine the Ideal Gas Constant (in units of ft.lbf/lb.R) for methane. Calculate the change in internal energy (in units of BTU) How much work is performed (in units of ft-Ibf) by the methane during this process?