How is relative centrifugal force calculated?

Relative centrifugal force (RCF) is a critical concept used in centrifugation processes within medical and laboratory settings. It refers to the force exerted on a sample during centrifugation relative to the force of gravity.

To calculate RCF, the formula incorporates the radius of the rotor (r) and the speed of the rotor in revolutions per minute (rpm). The specific factor used in the equation aligns with the relationship between linear acceleration and angular velocity.

The correct formulation of the RCF equation is given as:

RCF = (1.18 \times 10^{-5} \times r \times rpm^2)

This shows that the relative centrifugal force is directly proportional to the radius of the rotor and the square of the rotational speed.

The components of the equation highlight how increasing the radius of the rotor or its rotational speed will significantly increase the centrifugal force experienced by the sample. The choice clearly reflects this relationship, and the constant within this calculation (1.18 x 10^-5) is specific to typical units used in the field, ensuring that the resulting force is expressed correctly.

Thus, option B is accurate because it correctly embodies the formula for calculating relative centrifugal force in the context of laboratory practices involving centrifugation.