cecil mentioned in one of his recent answers that centrifugal force doesnt exist. i’ve heard the whole centri-(fugal/petal) shpeel before but i cant remember it. whats with centrifugal force “not existing”?
OK. You have a centrifuge for seperating materials of different density. You spin it really fast, and the more dense stuff goes to the outer edge, while the less dense stuff is moved inward. Or you tie a ball to a string and then spin the ball around you and it pulls on the string as it spins. “Centrifugal force is pulling the object outward, as you can tell from the tug on the string”, those not familiar with physics would say. Wrong.
More of a demonstration of inertia. Once an object is in motion, it tends to stay in motion in the same straight line, not in a circle. If a force is applied to it, such as the walls of a centrifuge, or a string, then it changes direction. This force is called centripetal. There is no centrifugal force. The tug on the string is just you applying an equal and opposite force to the centripetal force being applied by the string.
Of course, just because a force is fictitious, doesn’t mean that it isn’t useful. If you’re sitting on the Tilt-a-Whirl ride, the easiest explanation (from your point of view) of why you’re being pressed into your seat is that there’s a centrifugal force acting on you. For that matter, in tha context of General Relativity, gravity is trated as a fictitious force, too. It works.