Quick question on Gauss weapon recoil.

>From: Mark Urbin [email removed]
>Subject: Quick question on Gauss weapon recoil.

>  Just a quick question that someone better versed in physics than I can
>answer.  Why do guass rifles/pistols have a recoil value at all?
>As I understand it, a rifle that uses gunpowder has recoil because of the
>expanding gasses pushing back against the breach of the weapon (with the
>equal but opposite force shoving the bullet down the barrel).
>
>  A guass rifle works by pulling the bullet down the barrel with an
>electromagnetic field.  Thus, no pressure agains the breech.  I'm I missing
>something really basic here?

Well, some guy named Newton once said that 'For every action there is
an equal but opposite reaction'.  In other words, if a force is being
applied to the bullet, no matter the source of that force, there must
be another force acting against it.  You say that there is no 'pressure'
against the breech, but the electromagnetic field produces a force to
cause the bullet to accellerate, and this field must cause an equal
but opposite force to act on the barrel.  Now, if we're talking 'impulse',
well, that's a different story.

You may be getting confused with the similarity between the gauss gun and
the rocket launcher (or Bazooka, as I like to think of it).  A rocket
launcher is a tube open at both ends in which you place a small rocket.
The rocket accellerates without putting much recoil on the user.  Why?
Well, the rocket operates by accellerating small particles (exhaust)
in the opposite direction of it's direction.  An equal but opposite force
is applied to the rocket and causes it to accellerate forward.

Confusing, isn't it?  It's things like this that turns Engineering
majors into Business majors ;-).

No, I am not a Physics major, but as an Aerospace Engineer, I use that
law all the time.  So I _do_ know what I'm talking about.  ;-)

Bryce Harrington
The Aerospace Corporation
Flight Dynamics Department