Mechanical Properties of Fluids — Important Questions

Incompressible, Non-viscous, Irrotational flow, Steady flow

An ideal fluid has four main properties: (1) Incompressible - constant density, (2) Non-viscous - no internal friction, (3) Irrotational flow - smooth flow without turbulence, and (4) Steady flow - velocity at each point constant in time. Surface tension is not a defining property of ideal fluids.

Nature of liquid and solid, Temperature, Impurities in liquid

Angle of contact depends on: (1) Nature of liquid and solid in contact, (2) Temperature of liquid - higher temperature generally decreases angle of contact, and (3) Impurities present in liquid - can change the angle significantly. Volume of liquid and atmospheric pressure don't affect the angle of contact.

0.075 N/m

Using capillary rise formula: h = 2T cosθ/(rρg). Given: h = 0.03 m, r = 0.001 m, θ = 0° (cosθ = 1), ρ = 1000 kg/m³, g = 10 m/s². Rearranging: T = hrρg/(2cosθ) = 0.03 × 0.001 × 1000 × 10/(2 × 1) = 0.075 N/m.

Internal friction between fluid layers

Viscosity is the property of fluid by virtue of which relative motion between different layers of a fluid experience a dragging force. This dragging force is due to internal friction between the layers.