| [ KAIST ] in KIDS 글 쓴 이(By): mkjung (iSTHMUS) 날 짜 (Date): 2000년 11월 8일 수요일 오후 12시 45분 12초 제 목(Title): Re: 풍선은 왜 떨어지나요? That phenomena might be due to the 'leak' of ballon surface. The helium gas inside ballon diffused out and the air gas diffused into ballon through the leakage path. Accordingly, the gas density inside ballon becomes similar to that of external surrounding. ^^ ========== impossible. the pressure inside the ballon is far greater than the external air pressure. probabily small amount of air can diffuse inside the ballon but i don't think that is much. when you let the baloon stay forever, then the baloon shrinks eventually and will contains small amount of air inside the shrinked baloon. that tiny amount of air is the the amount of external air diffused inside the baloon. because that amount of air is so small, you can neglect the external air diffusing inside the baloon. QED. |