# Thermo dynamics gas process question help

Watch
Announcements
#1
Air contained in an upright piston/cylinder arrangement is compressedfrom an initial pressure of 10 atm. and volume of 0.42m3 to a finalpressure of 25 atm. If the atmospheric pressure is 1.013 bar and thecylinder contains 5kg of air, find the final temperature, the work done andthe heat transfer if the expansion occurs:
Isothermally,
Polytropically with an index of expansion of 1.3,
Isentropically with  = 1.4.

I know and have derived the relevant equations for the work done for each process i.e. for isothermal W=P1V1ln(P2/P1) and W = mRTln(P2/V2)

However using these equations I'm getting the work done to be 3.85KJ....I'm not converting the atm units into pascals and wondering if I should be doing this? Can anyone check if this is correct?
0
#2
don't worry just got it
0
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### Poll

Join the discussion

#### Should there be a new university admissions system that ditches predicted grades?

No, I think predicted grades should still be used to make offers (574)
34.37%
Yes, I like the idea of applying to uni after I received my grades (PQA) (687)
41.14%
Yes, I like the idea of receiving offers only after I receive my grades (PQO) (334)
20%
I think there is a better option than the ones suggested (let us know in the thread!) (75)
4.49%