# Homework Help: Find the final temperature? (Ideal Gas Law)

1. Jul 17, 2009

### elephunk

1. The problem statement, all variables and given/known data

Find the final temperature?

PV relationship -- PV^1.2 = constant

P1 = initial pressure = 720 kN/m^2
V1 = initial volume = 0.4 m^3
V2 = final volume = 1.2 m^3
T1 = initial temperature = 225 C

I managed to get the final pressure part out of the way but don't know where to head with the temperature. Can someone please point me in some direction?

2. Relevant equations

3. The attempt at a solution

The attempt at a solution and question can be found here: http://i45.photobucket.com/albums/f98/pastilles/Scan10012.jpg [Broken]

Last edited by a moderator: May 4, 2017
2. Jul 17, 2009

### Q_Goest

Hi elephunk, welcome to the board. Your work looks good... you did it right but it looks like you made a mistake in the math.

3. Jul 18, 2009

### elephunk

Hi,

Thanks for the welcome :)

Can you point me to where I am going wrong? Maybe looking at this at nearly 1am in the morning isn't good :(

4. Jul 18, 2009

### Redbelly98

Staff Emeritus
Your final pressure looks good, but your final temperature does not. The method seems correct, so it's probably a simple arithmetic error.

5. Jul 18, 2009

### Q_Goest

It looks from your attachment that you've calculated the final temperature to be 4 K. Is that what you meant the answer to be?

6. Jul 18, 2009