What is free surface in liquid?

Answer: In physics, a free surface is the surface of a fluid that is subject to zero parallel shear stress, such as the interface between two homogeneous fluids, for example liquid water and the air in the Earth’s atmosphere. Unlike liquids, gases cannot form a free surface on their own.

Why free surface of some liquid in contact with solid is concave?

Formation of a Meniscus When liquid water is confined in a tube, its surface (meniscus) has a concave shape because water wets the surface and creeps up the side. Mercury does not wet glass – the cohesive forces within the drops are stronger than the adhesive forces between the drops and glass.

Does the pressure change along a horizontal level?

The pressure is the same at all points at the same horizontal level within a homogeneous incompressible fluid. Above that, from B to A, is water of density 1.0 g cm-3, and above that is the atmospheric pressure of 101 kPa.

How is the surface of liquid?

The surface of any liquid is an interface between that liquid and some other medium. The top surface of a pond, for example, is an interface between the pond water and the air. Surface tension, then, is not a property of the liquid alone, but a property of the liquid’s interface with another medium.

What has no free surface?

Gases do not have free surfaces.

What is the pressure of a fluid at rest?

In addition to gravity, a fluid in motion will have surface forces due to viscous stresses. Viscous forces, however, for a fluid at rest are zero. The actual pressure at a given position is called the absolute pressure, and it is measured relative to absolute vacuum.

When fluid is at rest the total pressure act to the surface?

The total pressure is defined as the force exerted by a static fluid on a surface (either plane or curved) when the fluid comes in contact with the surface. This force is always normal to the surface. The center of pressure is defined as the point of application of the resultant pressure on the surface.

How many free surfaces does liquid have?

one
Solids have infinite free surfaces while liquids have only one upper free surface.

Why does free surface of liquid behaves like stretched membrane?

The liquid molecules on the surface experience a downward force. So, they have greater potential energy. In order to have minimum energy, the free surface tends to contract to minimum area and hence behaves like an elastic stretched membrane.

What is free surface in biology?

Epithelial tissue, because it forms coverings and linings, has one free surface not in contact with other cells. On the opposite surface, the epithelium is attached to underlying connective tissue by a non-cellular basement membrane, composed of carbohydrates and proteins. Next page >> Biology Dictionary >>

How many free surfaces liquid has?

Liquid contain only one free surface because force of attraction is less between the atom which do not allow it have more than one free surface. For example liquid occupy the shape of container in which it is poured.

What does the free surface of a liquid mean?

The free surface of a liquid just means the surface that is in contact with air. Like the horizontal surface of water in a glass. Or the top of the ocean where boats float.

Why are all free surfaces of liquids horizontal?

Thus, on the surface of the Earth, all free surfaces of liquids are horizontal unless disturbed (except near solids dipping into them, where surface tension distorts the surface in a region called the meniscus ).

What is the free surface of a liquid in gravitational field?

A liquid in a gravitational field will form a free surface if unconfined from above. Under mechanical equilibrium this free surface must be perpendicular to the forces acting on the liquid; if not there would be a force along the surface, and the liquid would flow in that direction.

How does surface tension affect the shape of free liquids?

In a free liquid that is not affected by outside forces such as a gravitational field, internal attractive forces only play a role (e.g. Van der Waals forces, hydrogen bonds). Its free surface will assume the shape with the least surface area for its volume: a perfect sphere. Such behaviour can be expressed in terms of surface tension.