Propulsion

How is propulsion achieved from butterfly arm action ?
Q. Please can someone explain to me, with reference to scientific principles, how is propulsion achieved from butterfly arm action ?
Asked by d_s_pickles - Wed Feb 24 07:26:48 2010 - - 3 Answers - 0 Comments

A. Propulsion in swimming is achieved from two forces. One is LIFT and the other is negative drag. Before we start, keep in mind that when you swim your hand should NOT move through the water. If it did, you'd go no where. Instead, your hand basically anchors in the water and your body moves over your hand. As your body moves PAST your hand, you lift your hand out of the water and move your hand forward so you can anchor it again. Consider treading and sculling water in an upright position. You don't push the water down to stay up. Instead (arms/hands only) you move your hands in an angled position. As your hands move, the water hits the palm of your hand and creates high pressure. On the back of your hand there is less pressure (if… [cont.]
Answered by academicjoq - Wed Feb 24 09:30:34 2010

Can we travel through space using an anti-gravity propulsion engine?
Q. Since gravity warps time and space, would it be possible to travel to distant galaxies fairly quickly if we could build a spacecraft powered by an anti-gravity propulsion device? If so, how would one be made? Are there any good plans on the internet? Would I need a pilot's license? Would the craft have to be approved by the FAA?
Asked by psychosolodiver - Thu Apr 23 11:18:41 2009 - - 4 Answers - 1 Comments

A. We'll never know until someone does it. Except perhaps in the very earliest universe, gravity is only attractive. Science fiction is not constrained by reality, though. A pilot's license would be needed only when the craft is in earth's atmosphere. And the FAA (in US airspace) would probably require only certain safety equipment. Look into regulations for experimental aircraft. Outside the atmosphere, who would regulate it? Just be careful not to damage satellites or space probes.
Answered by Frank N - Sat Apr 25 13:03:03 2009

Is being an Aerospace Propulsion Apprentice a good career field in the US Air Force?
Q. How good of a job is being a jet engine mechanic in the USAF? Like how are the work hours? What it's like working on fighter jet engines? How hard is it to work on jet engines? How long is the tech training for the career field? Thank you.
Asked by Marvin H - Wed Jul 7 22:53:16 2010 - - 2 Answers - 0 Comments

A. I think it would be a good job as it would translate easily to a civilian job. The Air Force is the military so the hours will be long. When you are not doing your job then you will probably be doing something like guard duty. I imagine it would be hard to work on jet engines but you will receive all the training you need to succeed. I'm not sure about the length of the school as I am an Army Vet but since working on jet engines is very technical I imagine the school will be long. ..
Answered by cyclone1164 - Wed Jul 7 23:11:32 2010