A piston/cylinder arrangement, shown in Fig. P2.125, contains air at 250 kPa and 300◦C. The 50-kg piston has a diameter of 0.1 m and initially pushes against the stops. The atmosphere is at 100 kPa and 20◦C. The cylinder now cools as heat is transferred to the ambient surroundings. 

a. At what temperature does the piston begin to move down?

b. How far has the piston dropped when the temperature reaches ambient?

c. Show the process in a P–v and a T–v diagram.

Transcribed Image Text:

Po 25 cm Air