Simple Piston-Cylinder Problem: problems with finding x and other information.

[WtKemper]

Homework Statement

An insulated Piston-Cylinder device contains .6kg of H20 at 600kPa Initially the volume of the system is .6m³. Now an electric resistor is placed in the tank and turned on for 10 minutes until the volume doubles.

Show this on a T-v diagram

What is final temp?

What is the power of the resistor?

Homework Equations

E_in-E_out=(Delta)E

The Attempt at a Solution

I began using Volume₁=.6 m³ Volume₂=1.2 m³. so then specific volume for initial = .1 m³/kg and for final specific volume = .2 m³/kg

I know that you can apply the equation above in some way. I'm just unsure how. My first thoughts were W_electric-Work_boundary=(delta)U from here can you change this to W_electric=(delta)U-Work_boundary=(delta)Enthalpy?

Both are within the range of specific volumes at the Pressure given so I know that it is a Saturated Mixture. But I'm stuck on where to go from here.I know that you have to figure out the ratio of the mixture, but I'm unsure what to use to find this. Any way enough rambling Thank you in advance! I would prefer help more than just answers

Oh I figure I can solve for x by using x= (v-v_f)/v_fg but I still don't understand how to find temp.
Also can pressure be condsidered constant in this case?

 

[WtKemper]

Anyone offer any help? sorry to bump so quickly

 

[RTW69]

I think you are superheated. State 1 has a specific volume of 1 m^3/kg if the mass of water in the cylinder is 0.6 kg. You can find T1, U1 etc. from steam table. Since the piston is allowed to float it looks like you have a constant pressure process from state 1 to 2 so you can find T2, U2 etc.