Density Of Water

Density Of Water is one of the most interesting concepts in Physics. Learn the concept of this topic in-depth along with other related concepts like the density of water at various temperature scales.

What is the Density of Water?

The density of a material is defined as its mass per unit volume. It’s a measurement of how tightly matter is packed together. The density of a substance can be explained as the relationship between the mass of the substance and volume it takes up.

The density of water is around approximately about 1 gram/ cubic centimeter. It is temperature dependent, but this relation is said to be non- linear and also it is unimodal in nature rather than monotonic. When it is cooled from the room temperature, the liquid water tends to become increasingly dense, as with another kind of substances, but approximately at about 4°C, pure water is said to reach its maximum density.

Density of Water

As it gets cooled further, it tends to expand and becomes less dense. This kind of unusual negative thermal expansion is related to strong, intermolecular forces, orientation-dependent, or interactions and it is observed in the form of molten silica.

The density of water at various temperature scales:

Temperature in 0C Density in kg/m3
100 958.4
80 971.8
60 983.2
40 992.2
30 995.65
25 997.04
22 997.77
20 998.2
15 999.1
10 999.70
4 998.97
0 999.83
-10 998.12
-20 993.547
-30 983.854

To understand the density of water, let’s do a small experiment, we will need a tall glass cup, honey, water, coconut oil and food coloring,

Step 1: Pour one-quarter cup of honey,

Step 2: Pour a one-quarter cup of colored water gently on top of the honey.

Step 3: pour a one-quarter cup of coconut oil on top of the colored water.

Water Density

Now, you will notice that different substance has different density, which means for the same volume different substances weigh differently, as they weigh differently heavier substances tend to settle at the bottom, like honey and lighter material like oil tend to float at the top.

Let’s extend our experiment further for more liquids, this time, we will use several liquids with different specific gravities, use the table given below for reference.

Material Density(gram/cm3)
Rubbing Alcohol 0.79
Lamp Oil 0.8
Baby Oil 0.83
Water 1.0
Milk 1.03
Liquid Soap 1.06
Corn Syrup 1.33
Maple Syrup 1.37
Honey 1.42

Practise This Question

Two uniform rods AB and BC of masses 1 kg and 2 kg respectively having lengths 2 m and 1 m respectively are joined to each other at B. They can rotate freely about B without any friction. The assembly is kept on a smooth horizontal surface as shown in figure.
A horizontal impulse P = 10 Ns is applied on the rod
AB at a distance 0.5 m from point B perpendicular to the rod

Angular momentum of rod BC about centre of rod BC just after application of impulse is