winglets - do they work...
4SPOOLED
I never said it didn’t have Kinetic Energy. It does. We just said Kinetic Energy isn’t a force.
I will leave it for you to make the relationship with Force, Momentum, Kinetic Energy and Work. I suggest you start with all their formulas. They speak a thousand words. Once you see how they are related you will finally grasp the concept we have been trying to explain to you.
Wouldnt then a A/C in flight under power/glide e.t.c have energy, and wouldnt this energy be called kinetic energy?
I will leave it for you to make the relationship with Force, Momentum, Kinetic Energy and Work. I suggest you start with all their formulas. They speak a thousand words. Once you see how they are related you will finally grasp the concept we have been trying to explain to you.
Good on you, 4 Spooled; it's not about being right or wrong or whatever, we're all on a learning curve anyway so none of us know it all.
One problem with a discussion like this is that it includes terms like energy, force, potential and so on that we use in everyday language, but which also have clear and specific meanings in physics, so the obvious start point in clearing up misunderstandings is to make sure we're all talking about the same things.
As I said, a high school physics book will go through all this stuff and hopefully present it in a logical progression; it isn't rocket science (well I guess it is in a way!) but it needs to be worked through to be clearly understood.
Very briefly, forces (gravity, lift, magnetic forces, direct pushes and pulls etc) working on masses will accelerate them. A number of forces working in opposing directions (as for an aircraft in flight) will either add up to a resultant force (which will accelerate the object) or balance eachother out (leaving the object in a steady state, eg a steady climb say).
Force = Mass x Acceleration (F = mA)
The important things to note when figuring out a force diagram like the old lift/weight/drag/thrust aeroplane pictures is that forces are vectors (ie. they have a direction as well as a magnitude) so you can look at them in various directions and see how they balance out (fore and aft, up and down or whatever).
Energy is something that an object or system can have that is broadly energy of motion (kinetic energy, 1/2 x mass x velocity squared) or potential energy (eg gravitational potential, mass x gravitational constant x height, mgh). Potential energy can also be things like the energy stored in a stretched spring, or in the chemicals of a battery etc)
Energy can be converted between forms (eg. potential to kinetic and back, as for the roller coaster; or kinetic into heat, such as when your brakes slow you down by using friction, and get hot).
I could waffle on all day but the best thing is just to get hold of a book and work through it.
Cheers
One problem with a discussion like this is that it includes terms like energy, force, potential and so on that we use in everyday language, but which also have clear and specific meanings in physics, so the obvious start point in clearing up misunderstandings is to make sure we're all talking about the same things.
As I said, a high school physics book will go through all this stuff and hopefully present it in a logical progression; it isn't rocket science (well I guess it is in a way!) but it needs to be worked through to be clearly understood.
Very briefly, forces (gravity, lift, magnetic forces, direct pushes and pulls etc) working on masses will accelerate them. A number of forces working in opposing directions (as for an aircraft in flight) will either add up to a resultant force (which will accelerate the object) or balance eachother out (leaving the object in a steady state, eg a steady climb say).
Force = Mass x Acceleration (F = mA)
The important things to note when figuring out a force diagram like the old lift/weight/drag/thrust aeroplane pictures is that forces are vectors (ie. they have a direction as well as a magnitude) so you can look at them in various directions and see how they balance out (fore and aft, up and down or whatever).
Energy is something that an object or system can have that is broadly energy of motion (kinetic energy, 1/2 x mass x velocity squared) or potential energy (eg gravitational potential, mass x gravitational constant x height, mgh). Potential energy can also be things like the energy stored in a stretched spring, or in the chemicals of a battery etc)
Energy can be converted between forms (eg. potential to kinetic and back, as for the roller coaster; or kinetic into heat, such as when your brakes slow you down by using friction, and get hot).
I could waffle on all day but the best thing is just to get hold of a book and work through it.
Cheers
.....so....how do winglets work then?
Well, glad you asked; firstly we must consider Bernoulli's theorem, the compressibility of a fluid, Reynolds numbers and of course the Heisenberg Uncertainty Principle, which leads us to the answer...I'm not certain!
Tinni..
Think you were taking the pi.....anyway ...http://www.boeing.com/commercial/aer...let_story.html will tell you some good info.
Think you were taking the pi.....anyway ...http://www.boeing.com/commercial/aer...let_story.html will tell you some good info.
Join Date: May 2005
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cheers for the help then guys, i have reread CPL aerodynamics anyway and booked myself into a 2 week Physics course in October at YPPH
Best to have all the tools of the trade at my disposal i suppose.
Best to have all the tools of the trade at my disposal i suppose.
