With the aid of a sketch, describe the motion of a solid particle settling in a liquid and discuss the effect on it of applying a centrifugal force. Define the terms Separating Effect, G, and Sigma Factor, Σ, as applied to centrifuges, and explain their meaning.

With the aid of a sketch, derive simple expressions for G and Σ for a thin cylindrical solid bowl centrifuge, carefully stating any assumptions that you may make.

Estimate the magnitude of G and Σ for a centrifuge 1 m long by 0.5 m in diameter operating with a liquid depth of 0.05 m and rotating at 1000 Hz (revolutions per second).