Weight loss in a vaccum

[rov1200]

Is the weight fractionally less if all the air is taken from one of those plastic containers that contain bedding or clothing?

[RATT23]

The weight is the same but the parcel would be less cumbersome.

[Westmerian]

The weight will remain exactly the same as the weight is determined by the force of gravity at the surface of the earth.

The weight can only change if the object is taken closer to the centre of the earth, i.e. down a mine shaft or flung into space, i.e. away from the earth's surface. The formula relevant to your question is F = mg, where F is the force (i.e.the weight) of the object, m is the mass, which never varies, and g is the acceleration due to gravity, which does vary. "g" is very much less on the surface of the moon for example.

[Bert]

I suppose you are thinking, if the air is removed, the weight should be less by the weight of the air removed. But the air in the bag is effectively supported by the pressure of the air outside the bag. When you remove the air, the volume of the bag decreases by an equivalent volume, so the support from the outside air decreases by an amount equivalent to the weight of the air removed. The mass of the bag and its contents will decrease, but the weight, as measured in normal conditions, will stay the same.

[rov1200]

I suppose the weight must be fractionally less

http://www.physlink.com/education/askexperts/ae650.cfm

but thanks anyway. I was trying to see the correlation with weightlessness in space.

[Bert]

I followed the link you provided, which simply says that air has weight - which you should have known anyway. My first answer tried to explain that the mass of the bag and its contents will decrease when the air is removed (obviously), but the weight (as determined on any sort of normal weighing machine of high sensitivity) will stay the same because the upthrust provided by the surrounding atmosphere will be reduced by exactly the same amount as the weight of the air removed. The only way that the weight would be reduced would be if you were able to weigh the bag (before and after) in a vacuum.