Concepts of a Piston cylinder device

[Xyius]

3.A cylinder/piston arrangement contains 5 kg of water at 100°C with x = 20% and the piston, mP = 75 kg, resting on some stops. The outside pressure is 100 kPa, and the cylinder area is A = 24.5 cm2. Heat is now added until the water reaches a saturated vapor state. Find the initial volume, final pressure, work and heat transfer terms and show the process on a P–v diagram.

At this point I really only need help with the concept behind the problem. Is it correct of me to assume the process is happening in constant pressure? I am unsure because the mass of the piston is given and I am assuming that the heavier the piston the higher the pressure below it.

Also he gives me the area of the cylinder, do you think he meant the area of the piston? Because I do not know what he means by the area of the cylinder. Would that include the piston bottom as one of the caps on the cylinder?

Thanks

 

[Xyius]

I emailed him, he did mean piston area. Although I am still unsure whether or not this would be constant pressure or not..