## how a centrifuge separates particles by density

I am confused on how a centrifuge separates particles by density. In wikipedia, it says it accomplishes this according to the sedimentation process, which appears to have something to due with an applied force or centrifugal force. It would seem like the more massive particles would remain closer to the axis of rotation due to their greater mass resisting centrifugal acceleration. Does any of the seperation occur during the angular acceleration of the device up to operating angular speed, or does it all occur while spinning at constant speed?

Any help will be greatly appreciated.
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 Recognitions: Homework Help Since the particles are denser than the fluid, they have a natural tendency to settle to the bottom, but they are prevented from this due to a low terminal velocity and turbidity of the suspension. The spinning motion creates extra "artificial gravity" and so increases the terminal velocity of the particles, allowing them to overcome the turbidity.

 Quote by turin Since the particles are denser than the fluid, they have a natural tendency to settle to the bottom...The spinning motion creates extra "artificial gravity" and so increases the terminal velocity of the particles, allowing them to overcome the turbidity.
Does this still apply to a horizontally spinning centrifuge? Is the "weight" of the denser particles greater in the horizontal direction as the centrifuge spins, and this overcomes the pressure of the liquid (due to the liquids "weight" in this direction), so the denser particles sink sideways? Is the "weight" the centrifugal force, and if so what applied force is the "weight" a reactive force to?