Air is contained in the insulated cylinder shown in Fig. P6.70. At this point the air is at 140 kPa, 25C, and the cylinder volume is 15 L. The piston cross-sectional area is 0.045 m2, and the spring is linear with spring constant 35 kN/m. The valve is opened, and air from the line at 700 kPa, 25C flow into the cylinder until the pressure reaches 700 kPa, and then the valve is closed. Find the final temperature.