2006-08-26 15:50:42 · 13 answers · asked by Quantum Eagle 1 in Science & Mathematics ➔ Physics
Helium has mass, while vacuum does not, by definition. An evacuated rigid vessel will be lighter than one filled with helium.
Of course, to hold up against the pressure of the atmiospher at 14.7 pound per square inch, the box would have to be very strongly built, and therefore quite heavy.
2006-08-26 15:55:11 · answer #1 · answered by Vincent G 7 · 1⤊ 0⤋
If both boxes weighed the same before one was evacuated and the other filled with helium, then the box containing a vacuum would be lighter because helium has weight and a vacuum contains nothing. However, if the type of vacuum you are talking about is a floor cleaner (like a Hoover) then the one containing helium would be lighter. :-)
2006-08-26 22:58:30 · answer #2 · answered by Gwen 5 · 1⤊ 0⤋
I am assuming that both boxes are identical, and able to withstand any outside forces such as air pressure.
Now to answer. One must understand precisely what is meant by "weight," and the environment in which any measurements are made. As others have stated, if we are containing some helium to a vaccuum, then the helium obviously has more mass. The point of inquiry probably stems from the buoyancy of helium. More precisely, if weighed on a scale on Earth, which box will read a higher weight? The scale will read the mass of the box plus the mass of the contents (converted to weight by multiplying the mass by gravitational acceleration) - the buoyant force, which is equal to the weight of the amount of air displaced by the box. To obtain this weight we simply take the volume of the box, find the mass of the amount of air it would take to fill that volume, and convert that mass to a weight by multiplying by gravitational acceleration. Now, since both boxes are rigid and identical, their volumes do not change, and therefore their buoyant forces do not change. Therefore, we only need to compare masses, and we find that the helium box is indeed heavier, even according to a scale.
Why is this counterintuitive? Because helium is lighter than the average person's "common sense" reference frame (air), but heavier than other things, like vaccuum. A balloon filled with atmosphere does not float up because the buoyant force is not quite strong enough to balence the downward weight of gravity; for every bit of air you put into the balloon, the additional weight is exactly cancelled by an increase in buoyant force, but no more than canncelled. The skin of the ballon provides the imbalance in favor of gravity. If you fill it with helium, or anything lighter than air (including vaccuum), then gravity is not enough to cancel the upward bouyant force, so up we go. filling a flexible container with vaccuum, of course, has its own problems.
2006-08-27 20:06:43 · answer #3 · answered by aristotle2600 3 · 0⤊ 0⤋
A rigid box with vacuum weights rVg less than the same box with helium, where r is density of helium, V is volume of box, and g is gravitational acceleration
2006-08-26 23:21:42 · answer #4 · answered by Duke 1 · 0⤊ 0⤋
Uh, something is always more than nothing. A rigid box with nothing in it will have less mass than a rigid box with something in it.
Helium is simply lighter than air. This is why a baloon filled with helium floats. If you put a baloon filled with helium in a vacuum, it would not float.
Got it? Good.
2006-08-26 22:59:34 · answer #5 · answered by Wicked Mickey 4 · 1⤊ 0⤋
the box... unless it was a ton of helium...Unless there was enough helium to out weigh the box... because even though there is no aair.. the box itself still has weight.. and scince helium can't lift the box, the box is heavier. (i think) So there would probably need to be billions of gallons of helium to make the helium heavier. But how do you weigh helium? If you weigh it while its in a tank then you have the weight of the tank and cant acuratly measure the wieght...
It depends oh how much the box weighs. prbably very heavy... and is the helium in a tank? does the tank count?
Very dificult question.
"see why vincent is at level 4 and pat is at level 2?"
Because he anwsers alot of questions and gets points every time he anwseres one, ans I don't come on here very often.
What do you have against me?
That's not even an anwser to the question
and why did you just talk about me and not about the other people who's anwsers are different than his?
2006-08-26 22:55:42 · answer #6 · answered by Pat 4 · 0⤊ 2⤋
a rigid box containing a vacuum
2006-08-26 22:57:08 · answer #7 · answered by Cass 1 · 1⤊ 1⤋
a vacuum has no weight. so helium will weigh more. but if you consider weighing vacuum with the box, then it may weigh more than helium.
2006-08-26 22:54:14 · answer #8 · answered by genetic_addict 2 · 0⤊ 1⤋
Helium, vacuum has no weight there Is nothing there!
2006-08-26 23:20:45 · answer #9 · answered by brown 25 2 · 0⤊ 0⤋
Helium weighs more than nothing.
2006-08-26 22:56:13 · answer #10 · answered by always a friend 3 · 1⤊ 0⤋