class 11 physics
Sol-1: To classify any flow as Rotational or Ir-rotational the angular motion of the fluid elements is analyzed. If the angle between the two intersecting lines of the boundary of the fluid element changes while moving in the flow, then the flow is a Rotational Flow. viscous, surface tension will develop.
Sol-2: Pressure is one type of external force that is exerted over a surface area of a material. It acts perpendicular to a surface. while
stress is one type of internal force that acts over a cross sectional area. It can also be parallel to a surface as well as perpendicular
Sol-3: Yes liquid are compressible, It is called compressibilty. Compressibility is the fractional change in volume per unit increase in pressure, examples are – water , mercury, Glycerine , ethyl alcohol etc