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Weight of flying objects

  1. Jan 6, 2008 #1
    I once read an article that said the average weight of a cloud is equal to eight elephants. I know that they are very massive and even larger so they are not that dense knowing this I pose two questions... How would one measure the wieght of a cloud when the density/volume is not uniform nor is it constant nor? and theorectically would one be able to feel the pressure change as a cloud flew over (could you feel the weight of the clouds)?
  2. jcsd
  3. Jan 6, 2008 #2
    No one can say exactly how heavy a cloud is. The way to measure its weight is this: they estimate the concentration of water droplet (very fine) then calculate the amount of water in cubic meter (or dm3 , cm3..). Then they have to estimate the whole volume of the cloud: the thickness, the widths.. And finally a multiplication.
    For the second question: I can tell you my experience. Once I cruised in the high mountain area by motorbike, and there were times some cloud flew across the trails. I can not feel any difference in pressure, only cooler a bit. Theoretically, the cloud must retain certain pressure equilibrium with the surrounding air, so there musn't much difference.
  4. Jan 7, 2008 #3


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    Really, the easiest way to determine for yourself what a cloud feels like, without leaving the ground, is to walk into a fog bank. Fog, after all, is just a cloud at ground level.
    That's one neat thing about living where I do. I can drive west, watching all of these honking huge clouds enveloping the mountains, and by the time I get to Banff or even Canmore, they aren't clouds any more; they're fog.
  5. Jan 9, 2008 #4
    The water droplets in a cloud are very small, small enough to be, buoyant and held up in the sky by air pressure. The reason you wouldn't feel pressure from a cloud passing over you in the sky is because it's held up by the air pressure, not you. I suppose it might increase the local air pressure slightly, though I'm not sure if that's true, but the reason why you don't feel the eight-elephants-worth of pressure on you is the same reason you don't feel pressure from the weight of the floor above you when you're in a multi-story building: because that weight is being held up by something other than your body.
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