Path: ...!eternal-september.org!feeder2.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Jim Pennino Newsgroups: sci.physics Subject: Re: Message to Bertie. Date: Sat, 9 Nov 2024 06:14:10 -0800 Organization: A noiseless patient Spider Lines: 58 Message-ID: References: <283234edb4860dffd533e3d6a13db815@www.novabbs.com> <0ap10l-17be1.ln1@gonzo.specsol.net> <0ec20l-3lr.ln1@gonzo.specsol.net> <55938031469c379f0b251eeca1c8e9b4@www.novabbs.com> <40678641e72a84ed7ded7dd3cf7a08b3@www.novabbs.com> <50330l-rso1.ln1@gonzo.specsol.net> <5fe71d9cea384745c8ebdef999fa3d40@www.novabbs.com> Injection-Date: Sat, 09 Nov 2024 15:16:03 +0100 (CET) Injection-Info: dont-email.me; posting-host="399dd6325e7f16c76aa3c5424c4202b1"; logging-data="4019095"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/slPvJLJz14BIB0IOrCe6P" User-Agent: tin/2.6.2-20220130 ("Convalmore") (Linux/5.15.0-125-lowlatency (x86_64)) Cancel-Lock: sha1:7waRB+2O6lFXyY4YYbKUvjftfAA= Bytes: 3340 bertietaylor wrote: > On Sat, 9 Nov 2024 3:54:15 +0000, Jim Pennino wrote: > >> bertietaylor wrote: >>> On Sat, 9 Nov 2024 0:41:01 +0000, bertietaylor wrote: >>> >>>> On Fri, 8 Nov 2024 21:29:06 +0000, Jim Pennino wrote: >>>> >>>>> bertietaylor wrote: >>>>>> On Fri, 8 Nov 2024 16:02:42 +0000, Jim Pennino wrote: >>>>>> >>>>>>> bertietaylor wrote: >>>>> >>>>> >>>>> >>>>>> Fool, with the low voltage given and its huge mass the momentum of the >>>>>> armature beats that of most high power rifle bullets. >>>>> >>>>> Utter nonsense, crackpot. >>>>> >>>>> Railguns don't have an armature, they fire projectiles through the air, >>>>> crackpot. >>>> >>>> The projectile is the armature, of the linear motor that in this case is >>>> the railgun, Penisnino, most extraordinary ignoramus. >>>>> >>>>> The muzzle energy of the very common 7.62x51mm NATO cartridge is >>>>> typically around 3,346 J. >>>> >>>> Weight of bullet is say 7g >>>> Muzzle velocity is 300m/s >>>> So ke is 0.5mv^2=0.5*.007*300^2=.0035*90000=3150J so okay >>>>> >>>>> The muzzle energy of the very common 5.56x45mm NATO cartridge is >>>>> typically around 1756 J. >>>>> >>>>> What is the muzzle energy of your low speed linear motor, crackpot?5 >>>> 0.5*4000*1.5^2= 2000*2.25=4500J, Penisnino >>> >>> Sorry we made a mistake above, it should be >>> 0.5 * 4 * 1.5^2 = 4.5 J and not 4500J. >>> >>>> which is greater than 3346J or 3150J or 1756J. >>> >>> We were wrong, but in Arindam's railgun design we do not talk of energy >>> except for efficiency we talk momentum. >> >> Railguns, actually ALL guns, are ALWAYS specified in energy as that is >> the important parameter and no one cares about momentum, crackpot. > > Moron, ALL guns are specified in terms of *muzzle velocity* Actually, it is the ammunition that is specified in terms of muzzle velocity, crackpot.