1. (50 pt.) Air contained in a 500 L rigid, insulated tank fitted with a paddle wheel, initially at 100 kPa and 310 K is stirred until its temperature becomes 470 K. Assume the ideal gas model for air. Ignore kinetic and potential energy changes. The environmental temperature is taken as 298 K. a) Determine the final pressure of air in the tank, in kPa. b) Using variable specific heat approach to evaluate the air properties, determine the work, in kJ, and the amount of entropy produced, in kJ/K. c) Using constant specific heat approach to evaluate the air properties, determine the work, in kJ, and the amount of entropy produced, in kJ/K. (Evaluate the properties of air at 300 K) d) Show the process on P-v and T-s diagrams.