Warm air is contained in a piston-cylinder assembly oriented horizontally as shown in Fig.P1.42. The air cools slowly from an initial volume of 0.003 m3 to a final volume of 0.002 m3. During the process the spring exerts a force that varies linearly from an initial value of 900 N to a final value of zero. The atmospheric pressure is 100kPa, and the area of the piston face is 0.018 m2. Friction between the piston and the cylinder wall can be neglected. For the air the piston-cylinder assembly, determine the initial and final pressure, each in kPa and atm.

A= 0.018 m Patm = 100 kPa Air Spring force varies linearly from 900N when V = 0.003 m' to zero when V = 0.002 m