Why do red blood cells collect at the bottom of a tube when centrifuged?

Red blood cells collect at the bottom of a tube when centrifuged due to their relatively high density compared to plasma and other components of blood. The centrifugal force generated during centrifugation causes the denser red blood cells to sediment and settle at the bottom, while the lighter components, such as plasma and platelets, remain above them. This separation allows for the easy collection and analysis of different blood components.