# Chapter 6 Physics | 1st Year

# Chapter 6 Notes | Physics 1st Year

## “Fluid Dynamics”

#### Index:

- Viscous Drag and Stokes’ Law
- Terminal Velocity
- Fluid Flow
- Equation of Continuity
- Bernoulli’s Equation
- Applications of Bernoulli’s Equation
- Torricelli’s Theorem
- Relation between Speed and Pressure of the Fluid
- Venturi Relation
- Blood Flow

#### Key Points:

- An object moving through a fluid experiences a retarding force known as drag force it increase as the speed of object increases
- A sphere of radius r moving with speed v through a fluid of viscosity η experiences a viscous drag force F given by stokes law F=6πηrv.
- The maximum and constant velocity of an object falling vertically downward is called terminal velocity.
- An ideal fluid is in compressible and has no viscosity. Both air and water at low speed approximate to ideal fluid behavior.
- In laminar flow, layers of fluid slide smoothly past each other.
- In turbulent flow there is great disorder and a constantly changing flow pattern.
- Conversation of mass in an in compressible fluid is expressed by the equation of continuity A1v1=A2V2 = Constant.
- The effect of the decrease in pressure with the increase in speed of the fluid in a horizontal pipe is known as venturi effect.