Chapter Five : Hydrodynamics
Definition
and Basic Concepts:
1-
Fluid:
Is a substance that can flow and doesn't has definite form.
2-
Steady flow in a tube require:
a- The liquid fill the tube
completely.
b- The quantity of liquid entering from one end of
the tube equals that goes out from the other end in the same time.
-
Equation of continuity:
-
For "N" similar branches:
A1v1
= N A2v2
The mass rate of flow is (Qm)
The volume rate is Qv
= AV m3/s
3- Viscosity : Is the property which is responsible for
resisting the liquid layers sliding above each other.
* The
coefficient of viscosity: vs
-
It is the tangential force acting on unit area to produce a unit
change in velocity between two layers 1 m apart.
- It is given
by:
-
It is measured in: kg m-1
S -1
Chapter Six : Gas Laws
Defintions
and Basci Concepts and Laws:
1-
The gas molecules are in continous random motion ( called Brownian
motion) and collide with each other and with walls of the container.
2- The intermolecular spaces between gas molecules are
large enough to permit gases to diffuse through each others.
3-
The Brownian motion is explained by Sir William Ramzy.
4-
Boyle's law :
At constant temperature, the volume of a fixed
mass of a gas is inversely proportional to its pressure.
5-
Charle's law :
* At constant pressure, the volume of a fixed
mass of gas expand by
of
its volume at 0 oC
for one degree raise in temperature. (voluem expansion coefficient of
a gas at const. pressure / unit degree rise of temperature.
*
At constant pressure, the volume of a fixed mass of gas is directly
proportional to its temperature at Kelvin scale,
6-
Pressure Jolly's law : * At constant volume, the pressure of a fixed
mass of gas increase by
of
its pressure at Oo
C for one degree raise in temperature . (The pressure expansion
coefficient of a gas at const. volume / unit degree rise of
temperature.
*
At constant pressure, the volume of a fixed mass of gas directly
proportional to its temperature at Kelvin scale
7-
The general gas law :
Chapter Seven : Kinetic Theory of Gases
1-
Postulates of kinetic theory of gases:
- Gas molecules are
perfectly elastic minute spheres, there volumes are neglegable
compared to the volume they occupy:
- The intermolecular
spaces, spacing gas molecules, are large enough to make the
attraction forces very small and can be neglected.
- The gas
molecules are in continuous motion as described by "Brown "
in the " Brownian motion ".
- All collissions with
each other or with the walls of the container are perfectly elastic.
2- The mole of any substance equals the molecular mass
number in grams.
3- Avogadro's number is the number of
molecules in one mole and equals 6.032 x 10 23
4- The gas density :
5-
The pressure of an enclosed gas:
6-
The K.E. of one molecule is taken as a measure to the temperature at
Kelvin Scale.
R
is the general gas const = 8.314 J/mole Ko
9-
The mass of one molecule "m":
