Air has weight--Gas law:
PV=WRT or W=(PV)/RT Where W= pounds of air, P=pressure, V=volume, R=gas
constant, T= temperature. All things being equal, the higher the pressure
the more pounds of air is in the tank.
MLD

wrote in message
...
Is a pressurized air object heavier?
In other words, is an object heavier when it contains compressed air
than when it's empty? For example, if I have a tire and weigh it
before pumping it full of air, will it be heavier after it's pumped
up? I say NO. A friend of mine insists it will be heavier once it's
filled with air. Who is right?

This is one of those fun topics that no one can agree on, and would
require a very accurrate scale that would most likely need to measure
down to the milligram.

Note: This would be regular compressed air from an air compressor, not
helium or another gas, which might make it lighter (even though I
highly doubt a tire full of air would float).

Mark