Concorde Vs Bullet

A friend and I were having a debate on a rumour that we once heard.
The rumour went along the lines, If concorde (or and other supersonic
aircraft for that matter) was fitted with guns then the bullets would
not be able to leave the muzzle or it would shoot itself if it fired
them while cruising. Assuming that the bullets velocity and the speed
of the aircraft are the same, what are your thoughts on what would
happen?

Next time you're on a plane, toss a bag of peanuts to someone in front of
you.

Never knew you could throw a bag of peanuts 500MPH, did you?

"rick_little99" wrote in message
oups.com...
A friend and I were having a debate on a rumour that we once heard.
The rumour went along the lines, If concorde (or and other supersonic
aircraft for that matter) was fitted with guns then the bullets would
not be able to leave the muzzle or it would shoot itself if it fired
them while cruising. Assuming that the bullets velocity and the speed
of the aircraft are the same, what are your thoughts on what would
happen?

Next time you're on a plane, toss a bag of peanuts to someone in front of
you.

I assume you mean in an open cockpit plane against the wind. Bullets
don't get to travel in a vessel like you and I do.

-Robert

From: Robert M. Gary - view profile
Date: Fri, Feb 17 2006 10:43 am
Email: "Robert M. Gary"
Groups: rec.aviation.piloting
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Next time you're on a plane, toss a bag of peanuts to someone in front of
you.


I assume you mean in an open cockpit plane against the wind. Bullets
don't get to travel in a vessel like you and I do.

-Robert




They do if you are a terrorist......

Ben

rick_little99 wrote:
A friend and I were having a debate on a rumour that we once heard.
The rumour went along the lines, If concorde (or and other supersonic
aircraft for that matter) was fitted with guns then the bullets would
not be able to leave the muzzle or it would shoot itself if it fired
them while cruising. Assuming that the bullets velocity and the speed
of the aircraft are the same, what are your thoughts on what would
happen?

Only if it's on a conveyor belt also going the speed of sound in the
opposite direction. ;^)

OK, i think you are looking at the problem a little too simply. It is
not just a relative motion issue. Air travelling towards the aircraft
would not be able to enter the muzzle (as it has nowhere to go). The
bullet would then travel down the muzzle at the speed of sound say (I
know it has to accelerate but lets just say it travels at a constant
speed) relative to the muzzle (i.e. the bullet would be travelling its
velocity plus that of concorde). Upon reaching the end of the muzzle
it would hit a wall of air travelling at the same speed as it so would
effectively instantaneously slow down to the speed of concorde. It
then could go one of 3 ways, it could bobble about in the space between
the end of the muzzle and the air around (the boundary layer), fly back
past the aircraft and possibly hitting the aircraft on the way past or
it could go bounce back down the muzzle.

NOt quite.

The bullet would not 'instantaneously' slow down. It has a given amount
of energy and is capable of supersonic speeds. The question would be
how long would it take to slow down to the Concorde's speed. If you
guess a second, and the bullet was fired along the flight path of the
airplane, it would have fallen 16 feet be the time it was traveling the
same speed, and another number of feet before it slowed down enough for
the airplane to catch up to it.

During WW2 some airplanes were said to have hit themselves with their
own bullets, but I think you can work out how that might happen with an
airplane diving under its own line of fire.

Finally, if you think you knew the answer, why did you post the
question?

I posted the question because i wanted to canvas opinion and spark
debate.....the very reason that these groups exist!

"rick_little99" wrote in message
ups.com...
I posted the question because i wanted to canvas opinion and spark
debate.....the very reason that these groups exist!

In other words, you're a a troll...

If its travelling at its own velocity plus the velocity of Concorde,
why would it instantly slow down to the speed of Concorde after exiting
the muzzle? Seems to me it would continue out the muzzle at whatever
its combined velocity was.