首先又看到好多物理竞赛题目好怀念，其次，想问一下这道题如果想做实验研究需要怎么做呢？应该是温度升高还是降低？
decrease slightly, because it's slightly compressed inside the balloon.
increase, because the contents of the cylinder are dramatically compressed.
increase because of friction
到底是哪一种？
12. Cold balloon
As air escapes from an inflated rubber balloon, its surface becomes cooler to the touch. Investigate
the parameters that affect this cooling. What is the temperature of various parts of the balloon as a
function of relevant parameters?