Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > sci.physics > #529301

Re: raining bullets

Show all headers | View raw

RichD <r_delaney2001@yahoo.com> wrote:
> In Physics 101, they teach that a bullet falls at the same rate 
> it rises, it's gravity etc.  Hence laws against firing into the sky.
> 
> But in the real world, there's air resistance, in both directions.  
> Question:  at what speed does a bullet actually hit the earth?  
> Assume .38 Special, if it matters.
> 
> --
> Rich

There are several things that matter.

It takes little thought to realize that bullets do not come down
at the same speed they went up.

The muzzle velocity of most handguns is just under 1.000 ft/sec and most
rifles around 2,300 ft/sec. Supersonic is 1,100 ft/sec. 

Once a bullet reaches apogee, it's vertical velocity is zero and the
only thing accerlating it is gravity, which means bullets, like everything
else, have a terminal velocity on the way down that is a function of
the drag and mass.

Bullets are spin stabilized so as to not tumble in flight.

If fired straight up, they are guaranteed to tumble on the way down.

At some angle less than straight up, they will not tumble and will
retain a lot velocity.

If they tumble, they have much greater drag.

Experiments have shown that the typical range of terminal velocities for
bullets is around 300 to 700 ft/sec.

After WWI, the US Army got concerned about the troops shooting into
the air at those new fangled airplanes and worried that the troops
might wind up shooting themselves in the process.

So in the 1920's a young junior officer named Hatcher, later General
Hatcher, was sent to a remote beach with troops, guns, and equipment.

They built a steel canopy for cover and built mounts to fire a variety
of guns, including rifles and machine guns straight up into the air.

After a little testing the exercise became a game to see if the troops
could catch the bullets in their helmets.

If you can find the whole story it is an interesting read.

I would not suggest anyone, well maybe one person, trying this at
home as a bullet at even 300 ft/sec would be a hell of a thump on
the head.



-- 
Jim Pennino

Back to sci.physics | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

raining bullets RichD <r_delaney2001@yahoo.com> - 2015-10-30 16:50 -0700
  Re: raining bullets R Kym Horsell <kym@kymhorsell.com> - 2015-10-31 00:10 +0000
  Re: raining bullets Fabian Russell <root@localhost.localdomain> - 2015-10-31 00:38 +0000
  Re: raining bullets jimp@specsol.spam.sux.com - 2015-10-31 00:40 +0000
    Re: raining bullets Sam Wormley <swormley1@gmail.com> - 2015-10-30 20:13 -0500
      Re: raining bullets benj <nobody@gmail.com> - 2015-10-30 21:39 -0400
      Re: raining bullets jimp@specsol.spam.sux.com - 2015-10-31 02:19 +0000
        Re: raining bullets Sam Wormley <swormley1@gmail.com> - 2015-10-30 21:39 -0500
          Re: raining bullets jimp@specsol.spam.sux.com - 2015-10-31 03:38 +0000
  Re: raining bullets "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-10-31 13:02 -0700
    Re: raining bullets Double-A <double-a3@hush.com> - 2015-11-01 13:46 -0800

csiph-web