Hi All. I was attracted to this forum when searching for what other people had done regarding a question about hook's constant applied to a balloon, and also dealing with the difference between the pressure of the air inside a balloon vs the atmospheric (outside) pressure. Since when the air is allowed to escape from an inflated balloon, it does so with vigor, we expect that the inside pressure is greater than that of the atmosphere. I worked out my own solution, but wanted to compare it with others, since it seemed counter-intuitive. I did find a post that also articulated doubts about the solution the author offered, which is that the difference in pressures inside and outside the balloon is inversely proportional to the radius--that the difference decreases as the balloon gets bigger! (my formula has an additional expression that bows out as the radius becomes larger) At any rate, this ought to be a simple problem, and one ought to deal with it honestly and forthrightly without a lot of hand-waving. I am not an expert, but hope to be able to contribute to a discussion now and then. I will have questions, and will sometimes propose solutions.