FLOATING AND SINKING OF OBJECTS

All of us must have observed that objects in water show different moving styles, some objects float on the surface of water and some sink. How density plays a major role in the sinking and floating of objects in liquid.

An interesting Experiment:

Let’s explore the idea through an experiment. Let’s take a jar filled with water, a few paper pins, hollow plastic material, and a bigger-sized onion. Immerse them in the jar and you will be surprised to observe that bigger and heavier objects like onions and plastics will float and smaller metal solid objects like paper pins will sink in the jar. 

Observation Table: Density of water 1g/cm3

REASON:This is because objects denser than water will sink and the objects floating on water are actually less dense than water. It is a comparative study where liquid is acting as a medium and any solid object floating shows it is less dense than water and vice versa.

Examples of Floating Objects: 

• Polystyrene Block: A polystyrene block floats in water due to its extremely low density of 0.05 g/cm³, which is significantly less than the density of water (1.0 g/cm³). 

• Wooden Block: A wooden block will be partially submerged but still float because its density (0.9 g/cm³) is slightly less than the density of water. 

• Iron Block: An iron block sinks because iron has a much higher density (7.9 g/cm³) than water. 

Floating Liquids: 

Floating is not exclusive to solid objects; liquids can also exhibit this behaviour. When considering two liquids with different densities, the less dense liquid will float on top of the denser one if the liquids do not mix. 

For example, Liquid A has a density of 0.76 g/cm³, while liquid B has a density of 0.93 g/cm³. Since 0.76 is less than 0.93, liquid A has a lower density. Consequently, liquid A will float on top of liquid B, provided the liquids do not mix.