Recent content by craglyboy

Homework Statement In a constant pressure process ant 1 bar determine how much heat must be added to raise the temperature of 2kg of compressed water at a temp of 50C so that it become superheated steam at a temp of 200C? u2=2659KJ/Kg Homework Equations W=-P(V2-V1) Q+W=U2-U1 The...

Nope ignore me

I got the values of U right I was just being an idiot and forgot the values were specific values and forgot factor in that I had 2kg of mass not 1. So I have got the right answer finally! Thankyou Lawrence C you have been extremely helpful!

thanks man can you see where i am being an idiot here, is it just for U2 I can't use that value because its not a pure dry mixture.

yeah Vf is tiny now I have found it got work done to -277.9KJ. for U1 I got 1670.4KJ from using the formula u=uf+x(ug-uf) and for u2 i thought because i know the specific volume look it up in the steam tables it comes to 2734KJ but I don't get the right answer for heat supplied. Because...

Is Vf zero?

thanks yeah that was just a typo supposed to be (Vg-Vf). The thing is I don't know values Vg and Vf are I have looked up in my steam tables and it says Vg is 1.694 at 1 bar but what is Vf?

Homework Statement http://img140.imageshack.us/img140/2963/isobaricsteam.jpg P1 and P2 are 1 bar. V2 4.812 and V2 specific volume is 2.406 X1=0.6 Homework Equations v=vf+x(vf-vg) W=-P(v2-v1) Q=(u2+pv2)-(u1+pv1) The Attempt at a Solution Hi guys first timer here...