3 Greens,
Or, to put Captain Stable's tale in a different way ..
(a) the ball reacts to the net or resultant force vector
(b) in a constant speed, level turn there are two vectors of interest - the horizontal (centripetal) force pointing to the centre of the turn, and the lift force vector pointing up. (Cast your thoughts back to private pilot licence principles of flight classes and that nice little diagram of a banked aircraft with lots of arrows going this way and that .. )
(c) the resultant of these two vectors is a third vector pointing more or less perpendicularly with respect to the aircraft .. the orientation of the resultant vector depends on whether the turn is balanced or not ... if the turn is balanced, the resultant vector will be normal (ie perpendicular to the aircraft) and the ball will be in the middle as it has no way of distinguishing between balanced flight with different angles of bank.
Or, if the above is confusing (at times I even confuse myself) ..
(a) contemplate a glass of water sitting in some sort of a string cradle and held by your good self at the other end of the string.
(b) at rest, the string hangs vertically as does the glass and the water surface (similar to a ball in its action) is horizontal. There is a vertical force vector only acting
(c) now start whirling the glass around you in a conical motion. You now have a vertical force (the glass doesn't fall down and smash on the floor) and a horizontal force (something has to be stopping the glass flying out and smashing against the wall). The resultant force is aligned with the string and the water surface is, again, horizontal with respect to the glass .. the water can't tell what angle the glass is at with respect to the real world.
... or have I just further confused the issue .... ?
Last edited by john_tullamarine; 29th Nov 2003 at 17:42.