What is surface tension describe the Laplace equation?

In physics, the Young–Laplace equation (/ləˈplɑːs/) is a nonlinear partial differential equation that describes the capillary pressure difference sustained across the interface between two static fluids, such as water and air, due to the phenomenon of surface tension or wall tension, although use of the latter is only …

What does Laplace pressure depend on?

According to the Young-Laplace equation, this pressure p depends on the surface tension σ and the radius of curvature r (for a sphere) or the main radii of curvature r1 and r2 (for a surface with any curvature):

How do you calculate Laplace pressure?

2γ/R is the Laplace pressure. The ΔP is 2 times the Laplace pressure since there is a complete sphere instead of a semi sphere on a layer of water. Based on the diameter, the pressure inside an air bubble in pure water, where γ = 72 mN/m at 25°C (298 K), can vary greatly.

Why is surface tension a tangential force?

The surface tension acts tangentially, even though the net force acts downward because of the following reasons: Particles on the surface have equal force along the side and due to this tensile stress is generated. The distance between the particles in the air is greater than the distance between particles in water.

Why surface tension is force per unit length?

Since it is completely spherical, we can describe its air/liquid interface in spherical coordinates as a circle. As surface tension only acts at the interface (i.e. the circle) we can consider it a force per unit length (of the circle).

What is Laplace’s law?

Simply stated the Law of Laplace says that the tension in the walls of a container is dependent on both the pressure of the container’s contents and its radius. If the pressure in a vessel is increased, we expect the wall tension to increase.

Why bubbles are round surface tension?

Bubbles are round — spherical — because there is an attractive force called surface tension that pulls molecules of water into the tightest possible groupings. In a bubble, the inward surface-tension forces of the water film are exactly balanced by the outward-pushing pressure of the air inside.