As Rod has already pointed out, that question is nowhere near clearly enough framed for anyone here to be able to answer it.
Stuff you can learn from this that might help in future:
<waffle>
Given a problem you don't know how to solve:
Make sure you understand what the quantity you're trying to obtain actually is.
Now make sure you understand the system, what "things" about that system affect the quantity you're trying to obtain, which of these "things" are fixed and how the rest of the "things" vary. You may find yourself with a choice of formulae. Don't discard any of them just yet.
Now compare the detail you've been given with the "things" you need to know. Hopefully most of them will already be there for at least one of the formulae you've found. Work out whether you can derive the remainder from what you have, look it up in some table of properties or make a reasonable assumption.
By that stage, you've done all the heavy lifting. The rest is just plugging numbers in.
Also some things about asking for technical help:
Understand enough about the question to be sure that you can explain what you need to know.
Put yourself in the place of the person you're asking for help. Work out what they'll need to know to be able to understand the question, work out how much of that they will already know and make sure you tell them the rest.
Additionally, on an internet forum like this, you need to bear in mind that there are lots of different sorts of engineers here - chemical, structural, electronic, mechanical, aero and on and on. All these engineering discipline use language in their own way, so it really helps if you lay out enough context in a question for people to understand what sort of engineering you're doing.
I wondered about that. I was trying not to assume that the OP either didn't realize the answer was in the question or doesn't know what atmospheric pressure is.
Rod Smith, P.E., The artist formerly known as HotRod10
