Let me give it a shot. The formula describing the relationship between force and acceleration is "F=ma", where F is the force applied to an object, m is the mass of the object, and a is the rate of acceleration. So to accelerate an object, be it a car, airplane, baseball or rocket ship, you must apply a force to it. Now on earth, objects are subject to a lot of forces (gravitation, wind, friction, bat swings, etc.) but in space there are essentially no forces on an object, unless it creates them itself.
OK, we want to accelerate our rocket ship, so we need to apply a force to it. But how can we apply a force when there's nothing to "push" against? Well, if we accelerate a DIFFERENT object, we have to create force to do it, and that same force will be applied in the opposite direction to our spacecraft. The "different object", in this case, is the hot gas ejected from our rocket motor. We create force by accelerating that gas. Now we COULD accelerate a heavy object (say a cannonball) to a low velocity to create our force (remember F=ma), but heavy things are expensive to get into space. So it makes since to accelerate a light object to a very high speed. Each molecule of gas accelerated to high speed results in a small force applied to the spacecraft. Accelerate enough gas molecules and you can create a significant force.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - A Lifetime of Farm Machinery - by Joe Michaels. I am a mechanical engineer by profession, specializing in powerplant work. I worked as a machinist and engine erector, with time spent overseas. I have always had a love for machinery, and an appreciation for farming and farm machinery. I was born and raised in Brooklyn, New York. Not a place one would associate with farms or farm machinery. I credit my parents for instilling a lot of good values, a respect for learning, a knowledge of various skills and a little knowledge of farming in me, amo
... [Read Article]
Latest Ad:
1964 I-H 140 tractor with cultivators and sidedresser. Starts and runs good. Asking 2650. CALL RON AT 502-319-1952
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
