In centrifugation, we use the force exerted by rotational motion in order to separate out components of a mixture that have different weights. This is very useful in separating components of a solution that are too light to be separated by sedimentation. We take some muddy water whose heavier particles have already been removed via sedimentation and a solution of calcium hydroxide. Fill two test tubes with muddy water and two test tubes with calcium hydroxide and place all four test tubes in the centrifuge machine as shown. After the machine is rotated for some time, we remove the test tubes and see that we get a precipitate of soil in the muddy water test tubes and a white precipitate in the calcium hydroxide test tubes with clear water on top in all the test tubes. The centrifugal force depends on the mass of the particles and the speed of rotation. With fast rotation even light particles get forced down to the bottom of the test tube as precipitate.