# Q & A: weight of helium balloon

Q:
My boss contends a helium-filled balloon weighs more on the moon than on Earth due to the moon's lack of atmosphere and thus no buoyant force. However, I can't reconcile the fact that adding mass (helium) to a deflated balloon on Earth would, by his definition, decrease the weight as the balloon starts to float, so I contend everything weighs less on the moon than on Earth. Does weight take more into account than just gravitational forces acting on an object, or is it strictly the vector pointing toward the center of the mass exerting the gravitational force on the object (and more importantly, who is correct regarding the weight of the helium balloon)? Thank you! -Tom
- Tom (age 32)
Milwaukee, WI
A:

You frame the question clearly enough that one can see that it's really just a matter of word usage. If you mean the weight you'd get on an ordinaty scale, then the He balloon has negatve weight on Earh and positive weight on the Moon. If you mean what the scale would read if the atmosphere is removed, due to direct gravitational force, then the weights are both positive and on Earth is bigger.

Either way you want to use the word is ok with me.

Mike W.

(published on 09/22/2020)