Finally we explore how the lift force varies with the angle of attack of the airfoil (which explains why aerobatic aircraft use symmetrical airfoils), and how stalling can result in a dangerous ...

By adjusting these so that the lift force points slightly forward, a designer can produce the equivalent of thrust. A sailboat tacking sharply upwind creates a similar force with its sail while ...

It will now be seen that in whichever direction the buckets are moved, the water will be directed to the force pipe in a stream, the continuity of which is only momentarily interrupted at the ...