Not to contradict any thing you say, but the speed of sound in bubbly
mixture (which one will have in a soda when the pressure is released)
is very low. -- of the order of feet per second.
Roger
On 5 Dec 2007, at 7:18 AM, karl shah-jenner wrote:
----- Original Message -----
From: "ADavidhazy" <andpph@xxxxxxx>
To: "List for Photo/Imaging Educators - Professionals - Students"
<photoforum@xxxxxxxxxxxxxxxxxx>
Sent: Wednesday, December 05, 2007 11:23 AM
Subject: Re: exploding soda can matter
: Marilyn,
:
: I am no physicist but I believe that once the bullet has entered the
: can and it is pushing its way to the other side it displaces liquid
: and this has to go somewhere and the only free space is the hole it
: placed where it entered ... so backwards. Later on the second, exit,
: hole appears and liquid is also able to go that way plus the bullet
: drags some along as well probably.
I'm hastily putting the finnishing touches to a presentation I have
to give at the local university tomorrow and at the same time
putting an application together for my old job at the local
photography college (yes, I'm thinking of coming out of my early
retirement!) but had to add to this a bit :)
Fired projectiles have a massive amount of kinetic energy which
converts pretty rapidly on contact to heat and also imparts a
substantial kinetic potential to the object it encounters, the
hydraulic effect of both boiling the a small portion of the
contents of the can it first encounters as well as the subsequent
release of gasses and the hydraulic hammer compound to expel fluid
at great force out the nearest exit point - which happens to be
where the bullet entered..
..still conveying energy as it passes out the other side another
exit point is created hence more fluid is explelled but withan
additional hydraulic shockwave /hammer brough about by the
compression shockwave built up ahead of the bullet as it passes
through the liquid (don't forget sound waves travel faster and with
less loss through liquid than through air) - and the can will often
burst from this added pressure!
easy!
karl
