This diagram shows a centrifuge used to separate solid particles suspended in a liquid of lower density. The container is spun at a rate of 540 revolutions per minute.

Calculate the centripetal force on a particle of mass 20mg at the end of the test tube.

An alternative method of separating the particles from the liquid is to allow them to settle to the bottom of a stationary container under gravity. By comparing the forces involved, explain why the centrifuge is a more effective method of separating the mixture.