to vorticey:
I see where you are coming from. You are concentrating on the feeling of being thrown outward, as in the car turning, or the girl holding on to the chain on the roundabout. That feeling of being thrown outwards is central to the difficulty in understanding centripetal, and the reason centrifugal is used as an easy substitute to promote understanding.
Perhaps this will help:
Going back to the logic steps I used above to describe centripetal, I used a car accelerating along a straight line as an example of a change of speed. Because speed had direction, and acceleration does too, when we depict the force, we can draw an arrow in the direction the car is traveling. in other words, to where the car is accelerating TO. Thats why centripetal was IN toward the centre of the circle: because it was an acceleration TO that direction.
So why do we feel flung outwards? When the car accelerates in a straight line do we feel a force? You betcha. We sink into the seat. We would get "flung backward" if the seat was not restraining us. In other words - we "feel" the acceleration in the opposite direction to which it is commonly thought of as being applied. In this case, the acceleration is going forwards, but we feel it going backwards.
Thus, when we are turning, we feel the opposite direction to the acceleration. I.E. we feel "centrifugal" because of the application of centripetal. Thus the force is centripetal (same as acceleration forward) and the sensation we feel is the REACTION (Thank you Mr Newton) to that force, but is NOT in itself a force.
Therefore the answer to Butch Grafton's FAA question on the "questions" thread is not amongst the solutions. The actual answer is that the oil goes to the edge due to the equal and opposite reaction of the attempt by the spin to apply centripetal force to it without restraining it. I dont mean to question the FAA, because they have never been inaccurate have they??
Thus, in answer to your statement above that there cannot be a force pulling the car into the corner, you can see that the force is only as imaginary as the force of straight line acceleration. If a force exists there, a force must also exist pulling the car into the turn. And we feel it just like the straight line acceleration - in the opposite direction to the force application - just like Mr Newton said we would.
I guess they gave centrifugal a special name to make it an easy to grasp concept, but at the end of the day, it is the same force we feel as we are resisting the change in speed (acceleration) of a car in a straight line. I dont know why the Latin Americans neglected to name that feel too??
Wait...what about "g forces"?
hope this helps.
Edited to try and address vorticey's specific statements rather than ramble on & on & on...woops, there I go again!
[ 04 December 2001: Message edited by: helmet fire ]