12 Physics . 2 Mechanical Properties Of Fluids Page 3

12 Physics 

 Chapter No. 2  Mechanical Properties Of  Fluids                                                     

Bubble posses two surface , hence the excess pressure will be

 (pi– po) = 4T/r

                                             

But the points B and D are at the same horizontal level. Thus, in order to maintain the same pressure, the mercury in the capillary rushes out of the capillary. Because of this, there is a drop in the level of mercury inside the capillary as shown in Fig. 

But the points B and D are at the same horizontal level. Thus, in order to maintain the same pressure, in the capillary water rises in the capillary. Because of this, there is a rise in the level of water inside the capillary as shown in Fig.

Hydrodynamics.

Distinguish between

Streamline Flow and Turbulent Flow

Viscosity:

For Viscous liquid flow different layers flow with different velocities. The central layer flows the fastest and the outermost layers flow the slowest.

Non-viscous flow

Critical Velocity and Reynolds number

 

Reynold number is a pure number. It has no unit and dimension.

 i) If Reynolds number is less than 1000, the flow of a fluid is streamline.

 ii) If Reynolds number is R greater than 2000, the flow of fluid is turbulent. 

 iii) If Reynolds number is R is between 1000 and 2000, the flow of fluid becomes unsteady, i.e., it changes from a streamline flow to a turbulent flow.

 Coefficient of viscosity:

 S.I. unit of viscosity is Ns/m2. 

Equation of Continuity:

                  Av = constant is called the equation of continuity in fluid dynamics.

 Bernoulli Equation:

  a) Speed of efflux:

b) Ventury tube:

c) Lifting up of an aeroplane:

 d) Working of an Atomizer

e) Blowing off of roofs by stormy wind