Unit-7: Chp-3: Fluid dynamics-Viscosity and Surface Tension

A brief view of its history:

The history of fluid dynamics, viscosity, and surface tension can be traced back to ancient times. The first known writings on fluid dynamics were by the Greek philosopher Archimedes, who lived in the 3rd century BCE. Archimedes studied the properties of fluids, such as their buoyancy and resistance to flow.

In the 17th century, the French physicist Blaise Pascal developed the principle of hydrostatics, which states that pressure in a fluid is transmitted equally in all directions. This principle is fundamental to our understanding of fluid dynamics.

In the 18th century, the Swiss mathematician Daniel Bernoulli developed the Bernoulli equation, which describes the relationship between pressure, velocity, and height in a fluid. This equation is used to explain many different phenomena in fluid dynamics, such as the lift of an airplane wing.

In the 19th century, the British physicist Isaac Newton developed the Navier-Stokes equations, which are the fundamental equations of fluid dynamics. These equations are very difficult to solve, but they have been used to study a wide range of phenomena, such as the flow of blood, the movement of clouds, and the formation of tornadoes.

The study of viscosity and surface tension has also had a long and rich history. In the 17th century, the French physicist Guillaume Amontons developed three laws of friction, which are also applicable to viscosity. In the 18th century, the British physicist Thomas Young developed the Young-Laplace equation, which describes the relationship between surface tension and the shape of a liquid surface.



The study of fluid dynamics, viscosity, and surface tension is a vast and complex field. It is a field that is constantly evolving, and there is still much that we do not know. However, the knowledge that we do have has allowed us to understand and control many different phenomena, and it has helped us to develop many important technologies.

Interesting Facts:

Some unknown facts about viscosity and surface tension:

• The viscosity of blood is affected by the temperature of the body. As the body temperature increases, the viscosity of blood decreases. This is because the molecules of blood move faster and have less time to interact with each other.
• The viscosity of honey is affected by the presence of pollen. Pollen particles can increase the viscosity of honey by providing a surface for the honey molecules to adhere to.
• The viscosity of lava can be affected by its temperature and composition. Lava that is hotter and more fluid will have a lower viscosity than lava that is cooler and more viscous.

• The surface tension of water is affected by the presence of impurities. Impurities, such as salt, can reduce the surface tension of water. This is because the impurities can disrupt the attractive forces between the water molecules.
• The surface tension of water can be increased by adding soap. Soap molecules can form a layer on the surface of the water, which reduces the surface tension.
• The surface tension of water can be used to create many different phenomena, such as the formation of soap bubbles and the ability of insects to walk on water.