What forces must be considered in non-inertial rotating reference frames?

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In non-inertial rotating reference frames, both real forces, such as centripetal force, and fictitious forces, like centrifugal force, must be considered. While objects appear at rest within the rotating frame, real forces still act on them, such as friction in the case of a block on a spinning turntable. The centripetal force, which is the net force directed toward the center, is essential for understanding motion from an inertial perspective. In the rotating frame, to apply Newton's laws effectively, the fictitious centrifugal force must be included alongside the real forces. Understanding these dynamics is crucial for accurately analyzing motion in non-inertial frames.
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dealing with non-inertial rotating reference frames, real forces such as the centripetal force need to be taken into account,or only the forces that can be really observed within the frame?

because from the perspective of the rotating frame, objects should be at rest. it only appears logical to replace the centripetal force with the centrifugal force when dealing in rotating frames.
 
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Real forces always count. "Real" forces have agents as opposed to "fictitious" inertial forces that are artifacts of using a noninertial frame of reference.

Note: "centripetal" force just means a force that acts toward the center (or the net force acting toward the center)--it's not a separate kind of force.

Example: Imagine a spinning turntable on which a small block sits. The block spins along with the turntable. From an inertial frame, the block is centripetally accelerated; the centripetal force is the friction between turntable and block.

From the rotating frame that very real friction force still acts, but now the acceleration is zero: In addition to the real friction force, one needs to add the "fictitious" centrifugal force in order to use Newton's laws.
 
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