logajan@ns.UUCP (John Logajan x3118) (02/14/89)
(Why I think) Projectiles from guns can be accelerated to speeds faster than the speed of sound in the propelling gases: Because the gas molecules traveling at near right angles to the direction of travel of the projectile can strike the projectile if it has a trailing conical section. That is, the ratio of projectile velocity to molecule velocity determines a slope at which an orthogonal molecule will just graze the projectile shape as it passes. Thus note, there is no upper limit on speed differential, as an appropriate slope can always be found. HOWEVER, the greater the ratio the more normal the collision and hence the less vector forward thrust produced. At some point the thrust produced will fall below other frictions and acceleration will cease. This same description holds true for sail boats (which explains why a sail boat can go faster at an angle to the wind than directly with the wind) and fresh watermellon seeds squeezed between the thumb and forefinger. -- - John M. Logajan @ Network Systems; 7600 Boone Ave; Brooklyn Park, MN 55428 - - ...rutgers!umn-cs!ns!logajan / logajan@ns.network.com / john@logajan.mn.org -
logajan@ns.UUCP (John Logajan x3118) (02/15/89)
I wrote: > (Why I think) Projectiles from guns can be accelerated to speeds faster than > the speed of sound in the propelling gases: I was refering to guns constructed so that the gases entered orthogonally at many ports along the length of the barrel, rather than end fired guns -- as someone else mentioned a few weeks ago -- sorry for the confusion. -- - John M. Logajan @ Network Systems; 7600 Boone Ave; Brooklyn Park, MN 55428 - - ...rutgers!umn-cs!ns!logajan / logajan@ns.network.com / john@logajan.mn.org -