Inner walls of the arteries are elastic in nature.

There is a plaque deposition inside of the artery.

The arteries which carry blood to the heart are called coronary arteries.

Bernoulli's principle: Kinetic head + Potentioal head + Pressure head = constant

The viscosity of a fluid is a measure of its resistance to deformation at a given rate.

Ideal fluid $\equiv$ non-viscous fluid.

$v_1>v_2>v_3>v_4>v_5>(=0)$ laminar flow

Viscous fluids

The applied force depends on

(i) Surface area, A

• $f \propto {A}$

(ii) speed, v $\quad f \propto {v}$

(iii) height, $h$ $\quad f \propto\frac {1}{h}$

$f \propto \frac {Av}{h}=\eta \frac {Av}{h}$

$\eta$: is called as Coefficient of viscosity

$\eta=\frac{F h}{A v}=\frac{Nm}{m^2} \cdot \frac{m}{s} .$

$=\frac{N}{m^2} \cdot s$ = pascal second (Pa·s).

The SI unit of viscosity is poiseiulle (PI).

1 poise = 0.1 pascal-second.

The flow rate of an fluid through the Pipe of raidius ,R., length L and having a pressure difference of $P_2-P1$ along the length.

• $Q \propto P_2 -P_1 \propto \frac {1}{L} \propto R^4$

• $P_2 >P_1$

• $Q= \frac{\pi R^4 (P_2 - P_1)}{8 \eta L}$

• $\eta^\prime = \frac{\pi}{8 \eta}$

Example:

The surface tension of a soap solution is 0.02 N/m what amount of work is requred for produsing a soap bubble of radius 0.05m ?

Solution

The work lone in making a soap bubble = Surface Tension $\times$ Total Surface Area

Surface Tension $\times$ (inner + outer) surface area

=$0.03_{N/m} \times 2\times 4\pi(0.05_m)^2$

$= 1.884 \times 10^{-3} J$

1. Density and specific gravity .

2. Pressure.

3. Different units of pressure.

4. Measurement of pressure Barrometer, U tube.

5. Pascal's principle.

6. Equation of continuity.

7. Buoyancy and Archimedes principle.

8. Surface tantional and surface energy.

9. Bernoulli's equation

10. The viscosity