Answer to Question #78189 in Mechanics | Relativity for Prerana

Question

Explain the working of a centrifuge.

Answer 1

Consider the use of a centrifuge to separate a powdered solid suspended in a liquid. A centripetal force is applied to the liquid via its container.
The centripetal force causes the liquid to move in a circle. If this force were removed the liquid would travel in a straight line.
Initially, there is no centripetal force acting on the particles in the liquid. They therefore do continue in a straight line, as the liquid is pulled round in a circle. This means that they move towards the bottom of the centrifuge tube. Due to the viscosity of the liquid, this motion does exert some centripetal force on the particles but not enough to prevent them from settling at the bottom of the tube.