Consider the frictionless piston-cylinder set-up with a linear spring as is shown below. The cylinder has an internal cross-sectional area of AC = 0.1 m2. Distances  y₁ and  y₄ are 0.005 m and 0.6 m respectively.  The mass of the piston
is m_p = 80 kg and the environmental pressure is P0 = 100 kPa. Assume  g = 10 m/s2. Initially the
set-up contains saturated liquid water at T₁ = 30ºC.  950 kJ of heat (1Q5) is now added until the piston is finally forced onto the upper stops.  In total, 60 kJ/kg of specific work (1w5) was done.  The following states are of interest:
 
State 1: Initial state as is shown
State 2: Piston leaves the bottom stops
State 3: Piston gets into contact with the spring
State 4: Piston gets into contact with the upper
stops, Pressure is 1 MPa.
State 5: Final state. 
 
Calculate the following:
a)  P1
b)  P2
c)  y3 
d)  T5.