Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!decvax!ucbvax!ucbcad!tektronix!hplabs!sri-unix!David.Smith@CMU-CS-IUS.ARPA From: David.Smith@CMU-CS-IUS.ARPA Newsgroups: net.space Subject: Rocket thrust Message-ID: <894@sri-arpa.UUCP> Date: Fri, 15-Jun-84 13:29:00 EDT Article-I.D.: sri-arpa.894 Posted: Fri Jun 15 13:29:00 1984 Date-Received: Tue, 19-Jun-84 01:07:51 EDT Lines: 22 n mass. In the rifle analogy, the reaction mass comprises not just the combustion products, but also the rifle and the person holding the rifle. There is a limit to the rate of expansion of combustion products, even if uncontained in space. A rifle ensures that most of that rate gets transferred to the bullet. A rocket lets most of it get away, since the exhaust is only confined by its own inertia. A rocket in the atmosphere gets a little bit of assistance in confining the exhaust. David Smith