Path: ...!news.nobody.at!weretis.net!feeder8.news.weretis.net!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail
From: liz@poppyrecords.invalid.invalid (Liz Tuddenham)
Newsgroups: sci.electronics.design
Subject: Re: OT: Repeatably lobbing "projectiles"
Date: Sun, 24 Nov 2024 19:43:14 +0000
Organization: Poppy Records
Lines: 24
Message-ID: <1r3jl5k.letnj9o06qnfN%liz@poppyrecords.invalid.invalid>
References: <vhmm2k$hpg1$1@dont-email.me> <1r3f73p.7qcctfx0kmuN%liz@poppyrecords.invalid.invalid> <vhr49f$1cecu$3@dont-email.me> <1r3h153.1cx8mcd1gq3vkiN%liz@poppyrecords.invalid.invalid> <vhsdel$1m8od$1@dont-email.me> <1r3hsnb.hhqlyd84n8huN%liz@poppyrecords.invalid.invalid> <vhtndk$1ss17$5@dont-email.me> <1r3ixnc.191bu03ftabi8N%liz@poppyrecords.invalid.invalid> <vhv4iq$27kpu$1@dont-email.me> <1r3j622.inw1grtpjediN%liz@poppyrecords.invalid.invalid> <vhvsaf$2bi55$1@dont-email.me>
X-Trace: individual.net CmapnXXo8317UO63NERN0QgU47KUjezamdYAIwGfpHn++AWar7
X-Orig-Path: liz
Cancel-Lock: sha1:cUpjrdK07irvjQONp8Kw1DY9j0k= sha256:pQPIRHO3bAM6lpicj0H05tQLq6mekESsyLXPZuK8XsQ=
User-Agent: MacSOUP/2.4.6
Bytes: 1996

Don Y <blockedofcourse@foo.invalid> wrote:

> On 11/24/2024 7:36 AM, Liz Tuddenham wrote:
> > Don Y <blockedofcourse@foo.invalid> wrote:
> > 
> > [...]
> >> Couldn't the plunger be "polystyrene cup shaped" so it stays behind
> >> for reuse, automatically?
> > 
> > No - because the cup has to be in contact with the projectile to
> > maintain its shape while it is accelerated up the barrel.  That means
> > the air pressure must be behind the cup.
> 
> I don't understand.  What's the difference between the cup BEING
> the top of the plunger (which has air pressure behind it) and
> leaving the barrel WITH the projectile?

The plunger has to stay behind the air inlet so as to block the back end
of the barrel.

-- 
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk