Path: csiph.com!eternal-september.org!feeder.eternal-september.org!nntp.eternal-september.org!.POSTED!not-for-mail From: Christopher Howard Newsgroups: sci.physics Subject: ideal gas law - pressure and mass question Date: Fri, 17 Apr 2026 11:39:55 -0800 Organization: A noiseless patient Spider Lines: 22 Message-ID: <87a4v1wf3o.fsf@librehacker.com> MIME-Version: 1.0 Content-Type: text/plain Injection-Date: Fri, 17 Apr 2026 19:40:00 +0000 (UTC) Injection-Info: dont-email.me; posting-host="8ec314d79b2c26f36e53c6706996638d"; logging-data="2859023"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19fHuPnhpFtotutmp6OwG+NLh1eKaaUrqE=" User-Agent: Gnus/5.13 (Gnus v5.13) Cancel-Lock: sha1:/TBLfalkGiltsO1zmay3Cf98Kqk= sha1:Sksojx4PVn/odhn/N3FT3t+Kj4Q= Xref: csiph.com sci.physics:895727 Hi, I tried to work something out on paper, but the result seems counter-intuitive, so I'm wondering if my mathematical formulation is wrong, or just my understanding of the concepts. Assume we have pumped some mass of an ideal gas into a very strong container, i.e., no change in volume possible. And assume the container is such a good heat insulator that loss of heat to the environment is negligible. But say that we are able to add heat to the container, maybe through an electric heating element inside. And lets say I apply a steady amount of heat transfer, say 80 watts. The pressure will increase. My question: will the rate of pressure change, over time, be dependent on how great a mass of gas I have originally pumped into the container? I.e., will my pressure gauge needle swing more slowly if I have 10 kg of the gas in there, as opposed to 1 kg? I've been assuming also that the specific heat of the gas remains the same throughout the whole process, which I believe is a justifiable assumption under practical circumstances (...?) -- Christopher Howard