(a) A vertical, frictionless piston-cylinder device contains a gas at 180 kPa absolute pressure (gas is in State 1 as shown). The atmospheric pressure outside is 100 kPa, and the piston cross-sectional area is 25 cm². Determine the mass of the piston (in kg). Assume g=9.81 m/s².

(b) Heat is now added to the gas, causing it to slowly expand. State 2 is reached when the piston is just in contact with the stops. (The stops are there to prevent the piston from moving upward.) From State 2, heat continues to be added to the gas until it reaches State 3, at which point the pressure is 1.618 times P₁. Show the entire process, from State 1 to State 3, on a P-v (i.e. pressure vs specific volume) diagram. You do not need to include numerical values of P or v in your sketch, but show clearly the three states and the paths between them

 

Transcribed Image Text:

g gas State 1 g gas State 1