I'm not sure why you keep refering to rockets; I think there is a fairly
exact analogy
gas spewing out --> recoiling Rocket
Bullet --> recoiling gun
______________________
I.e.
Gases flying out the back end of the rocket are to the metal of the
rocket
As
the bullet flying out the end of the gun is to the recoiling gun
___________________
A gun recoils because you throw bullets out its end (i.e. you throw
momentum out one end)
A rocket recoils because you throw mass (gas) out its end (i.e. you
throw momentum out one end)
_______________________
Joel Rauber
Department of Physics - SDSU
Joel.Rauber@sdstate.edu
605-688-4293
| -----Original Message-----
| From: phys-l-bounces@carnot.physics.buffalo.edu
| [mailto:phys-l-bounces@carnot.physics.buffalo.edu] On Behalf
| Of Bernard Cleyet
| Sent: Friday, October 06, 2006 3:07 PM
| To: Forum for Physics Educators
| Subject: Re: [Phys-l] Ballistics divertissement
|
| "I think they have the protocol wrong. Both military and
| civilian firing squads had one rifle loaded with a blank and
| the rest with live bullets ..."
|
| Yes, and I think the reason is so all may think they didn't
| kill the victim, which implies ....
|
|
| I asked an employee at trigger hill -- he immediately pointed
| out as stated in this thread, the smaller charge. He thought
| there would, all being equal xcept the bullet, be a
| difference until I pointed out rockets don't use bullets.
| Then he told me the "gun" shop in Watsonville rents and has
| their own range. He also agreed immediately that if the
| difference was slight or non-existent the perception would
| mirror the belief. [I should have asked if he got a good
| grade in Physics!]
|
| So if this thread doesn't convince me, I'll spend some money
| in Watsonville, if I can convince them to let me hang the
| fire arm as a ballistic pendulum or clamp it to a wheeled platform.
|
| bc, who notes JS's argument suggests rocket engineers prefer
| denser fuels (w/ the same specific energy), and wonders when
| JD will enter.
|
| p.s. he also thinks JS has confused JC for bc.
|
| Kilmer, Skip wrote:
|
| >Although not really germane to the question, I think they
| have the protocol wrong. Both military and civilian firing
| squads had one rifle loaded with a blank and the rest with
| live bullets. A single shot is considerably less likely to
| result in death than 5 (or 11).
| >Are we getting gruesome, or what?
| >skip
| >
| >-----Original Message-----
| >From: phys-l-bounces@carnot.physics.buffalo.edu
| >[mailto:phys-l-bounces@carnot.physics.buffalo.edu]On Behalf Of Brian
| >Whatcott
| >Sent: Friday, October 06, 2006 10:25 AM
| >To: phys-l@carnot.physics.buffalo.edu
| >Subject: [Phys-l] Ballistics divertissement
| >
| >
| >I watched a TV movie last night of the CSI variety, which revolved
| > around twelve jurors, dismayed by a torturer/killer going
| > free, who conspired to train themselves to execute (!) a
| firing squad.
| >This program emanated from a country which does not
| >(publically) endorse state-sponsored torture, so there was
| a dramatic
| >element.
| >
| > A policeman casually mentioned, the shooters would know
| which of the
| >twelve had the live round in the rifle - the recoil of course.
| >
| >So here's the point that puzzled me: supposing that each
| round had the
| >same propellant charge, what would be the magnitude of the
| >recoil/difference?
| >
| >I expect that it would be reasonable to have some numbers,
| > so let me pull these out of the air:
| >bullet: 0.030 kg
| >muzzle velocity: 500 m/s
| >
| >
| >
| >Brian Whatcott Altus OK Eureka!
| >
| >
| >_______________________________________________
| >Forum for Physics Educators
| >Phys-l@carnot.physics.buffalo.edu
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| >
| >_______________________________________________
| >Forum for Physics Educators
| >Phys-l@carnot.physics.buffalo.edu
| >https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l
| >
| >
| >
| >
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