Do pop cans weigh more crushed?

Question

Do pop cans weigh more crushed?

Answer 1

Think about this one. There is no chemical change (burning, melting, etc.) and no part of the can has been taken away or in any way removed. Everything is still there, it's just been crushed and crumpled into a new shape.

The weight it the same. However, since it is now smaller, it is more dense. Try floating a crushed and uncrushed can in water and you'll see the difference.

Answer 2

No.

In a perfect environment, they would weigh slightly less, since all the air is removed from them.  but the amount is so tiny as to be almost unoticeable.

However, crushed cans take up less space than uncrushed cans, so you can fit more crushed cans into a given space.  so a "cubic foot" crushed cans would weight more than a "cubic foot" of uncrushed cans since there would be more cans in teh "cubic foot".

BTW Gergley -- You cannot create or destroy ENERGY.  We create and destroy (especially destroy) matter all the time -- like a cigarette or coal in a furnace.

Answer 3

Maybe.

If you compress a spring - where is the energy stored?  The answer is that the spring gets slightly heavier.  e = mc^2.  Mind you, c^2 is a big number, so the mass doesn't change by a heck of alot.

So the question is, does the crushed can have more energy than an uncrushed can?  I think the answer is "no", but it's likely more complicated than the idea that it won't spontaneously pop out.

Answer 4

No. You can't 'create' or 'destroy' matter, so it won't weigh more after a simple shape change, even if their mass is concentrated in a smaller volume.