How does altitude effect buoyancy?

Question

If a person were to weigh themselves on an airplane and the airplane were to suddenly loose pressure, would he or she weigh less due to a smaller buoyant force?

Answer 1

Buoyancy is less so the passenger's weight measured inside the plane increases. However note that the total weight of the plane would decrease a little, because the plane no longer is carrying the denser air it had before the pressure loss. The change in the passenger's buoyancy doesn't affect this, since a closed container sees the weight of all the mass inside, regardless of any internal buoyancy that may occur.

Answer 2

the same, because the scales are zeroed out before the person steps on them. if the person was standing on the scales when the plane lost pressure, then the difference in pressure * the area of the scales would be the diffence in weight.