The two questions that were on my exam, to be honest, i didnt answer because I didnt understand it enough to do so. But Im willing to learn and be shown the way to a legit answer, so please dont immediately give me answers. The questions are like this: The density of air near the earth's surface is 1.29kg/m3. If a helium ballon with a mass of 1 kg floats in air without rising of falling, what is the minimum volume of helium in the ballon? Show your calculations.(Presume that the mass of the material making up the balloon is negligible.) -- and -- A balloon filled with one liter of air is tied to a brick and dropped from a height of 4600 m above sea level. If the atmosphere 4600 m above sea level has a pressure of 70 kPa, what will be the volume of the balloon when it reaches sea level? Show your calculations. (Hint: atmospheric pressure at sea level is 101.3 kPa.) Thank You for reading my post.