Zeev's Turnips Talk Politics (ZTTP)

[fung_derf]

Zeev.....I'm back again with further physics questions for you. The quote below was found from a physics professor at Phoenix University and someone brought it up as an opposing view in response to the theory that steam in a sealed box would have the same weight as that of ice or water. Now, in my opinion, comparing pigeons and steam is not accurate, but it does bring up an interesting point. I was wondering on your thoughts?


A very simple chemistry experiment, which starts from a solid,
Potassium Chlorlate, and ends up with a solid and a gas (Oxygen).
Specifically interesting is the second paragraph - the line that
reads "The potassium chlorate decomposes to give oxygen gas and
potassium chloride; hence the weight loss in grams equals the grams of
oxygen produced."

More supporting examples....
weight = mass x gravity
density = mass/volume

I'll let you do the math, but it equals out that
weight=density x gravity x volume

As a substance moves from solid to gas, it becomes less dense.
Therefore, the weight would decrease by the above formula.

Another common sense example that I really liked....say you have a U-
haul truck on a scale. Sitting on the floor of the cargo area are a
bunch of pigeons. The truck weighs some amount. The pigeons then all
fly up at the same time, and are flying about in the cargo area. Does
the truck weigh the same? Nope.