<h1>The Pendulum Rocket Fallacy</h1> This guy should read this (
http://www.ninfinger.org/%7Esven/rockets/gcsfaq.html ) and this (
http://www.quantumscientific.com/modroc4.html ) before he becomes like a mexican tostitos sauce ...
In short for the rest of us, here is the explanation:
The balancing act is so difficult that many intelligent amateurs have tried building rockets that have their engines at the top.
Intuition says that when you lift something from the side, it's center of mass will swing below the point of support and stabilize, like a pendulum that eventually lines up right under your point of support after swinging back and forth a bit.
So far so good.
By putting the engine at the top of their rockets, some amateur rocketeers intend to keep them upright during lift off. They think their rockets won't fall over like a pool cue without the juggler, but will just wobble back and forth under the rocket engine's support, like a pendulum, until it is completely stable.
One of the two main places where intuition goes awry is in forgetting that a rocket engine is rigidly connected to the rest of the vehicle, so the engine's support of the vehicle changes direction along with the center of mass.
The other place where intuition goes awry is assuming that larger masses will fall faster than lighter masses. Galileo showed this false when he dropped two differing weights from the Leaning Tower of Piza and they both hit the ground at the same time. The top and bottom of a pendulum rocket will fall at the same rate so gravity doesn't stabilize it.
In outer space, such a rocket would just go round and round in a big circle. In Earth's gravity, however, the whole circle falls at 9.8meters/sec**2.
If you are wondering how simple model rockets with fins manage to fly straight up, the short answer is, "Because that's the direction they were going when they got going fast enough that the wind on their fins made it hard to turn any other direction."
------------------
wiZd0m
Fortune Pussy Adult Links