Mechanical Properties of Fluid

class 11 ncert physics mechanical properties of fluids

Pressure (P)

Defined as P = F / A, where F is force and A is area.

Fluid Column Pressure Formula

P = hρg, where h is the height of the fluid, ρ is the density, and g is the acceleration due to gravity.

Pascal's Law

Pressure applied to an enclosed fluid is transmitted undiminished to every portion of the fluid and the container's walls.

Hydraulic Lift

A system where forces F1 and F2 are related through their respective areas A1 and A2 due to Pascal's Law.

Viscosity (η)

A measure of a fluid's resistance to flow, given by η = (F * L) / (A * V).

Newton's Law of Viscosity

Describes how the coefficient of viscosity (η) relates force (F), area (A), velocity gradient (V/L), and length (L).

Stokes’ Law

Describes the force acting on a sphere moving through a viscous fluid, given by F = 6πηrv.

Equation of Continuity

A1v1 = A2v2, representing the conservation of mass in fluid dynamics.

Bernoulli’s Theorem

States that the total mechanical energy for flowing fluids is constant, expressed as P + (1/2)ρv^2 + ρgh = constant.

Surface Energy

The energy required to increase the surface area of a liquid, given by Surface Energy = TΔA.

Excess Pressure in a Liquid Drop

Inside a liquid drop, excess pressure is ΔP = 2T/r.

Excess Pressure in a Bubble

Inside a bubble, excess pressure is ΔP = 4T/r.

Capillary Rise Formula

Describes how liquids rise in a capillary tube: h = 2Tcosθ / ρgr.

Viscosity Defined

It's the measure of a fluid's resistance to flow, e.g., honey has a higher viscosity than water.

Bernoulli's Principle Simplified

Faster-moving fluids exert lower pressure, applied in real-life scenarios like airplanes and chimneys.

Surface Tension Explained

It’s the tendency of liquid surfaces to minimize their area, observable in soap bubbles and water droplets.

Capillarity Overview

Describes how liquids rise or fall in a capillary tube due to adhesion and cohesion forces.

Streamline Flow

Characterized by smooth and regular fluid movement.

Turbulent Flow

Characterized by chaotic and irregular fluid movement.