Mechanical properties of fluids

• The pressure at any point within the fluid is equal to the weight per unit area (force/area) acting on that surface.
• Viscous forces are proportional to velocity gradient, with higher velocities resulting in greater drag force.
• The viscosity of a fluid is the resistance to flow.
• If there are no external forces acting on the fluid, then the net force on the fluid is zero.
• When we study or deal with the fluid at rest called as fluid statics
• The branch of physics that deals with the study of the fluids when it is in motion is called he fluid dynamics
• Fluid mechanics can be classified into two categories based on the nature of the fluid: Fluids at Rest and Fluids in Motion
• Incompressible means that the volume remains constant regardless of changes in pressure
• A fluid is considered compressible if its bulk modulus of elasticity (B) is greater than 109 N/m2
• Air is an example of a compressible fluid
• Compressibility is defined by the ratio of change in density to initial density
• Density is defined as mass per unit volume
• Pascal's law states that pressure applied to any point within a confined liquid will result in equal pressure being transmitted throughout the entire system.
• Pressure is defined as force per unit area
• It is the force exerted by liquid on any surface in contact is called thrust