Chapter Three : Light
1-
Laws of reflection of light:
1st law: angle of incidence =
angle of reflection.
2nd law: the incident light ray, the
reflected light ray and the normal to the reflecting surface at the
point of incidence, all lie in one plane perpendicular to the
reflecting surface.
2- Refraction of light rays between
two media is due to the difference in light speed in the two media
v1,
v2.
3- Laws of refraction of light:
1st law: relative
refractive index between two media :
2nd
law " The incident light ray, the refracted light ray and the
normal to the separating surface at the point of incidence, all lie
in one plane normal to the separating surface."
4-
The absolute refractive index :
5-
The relative refractive index =
6-
"Snell's
law":
n sin
= const
n1
sin
= n2sin
7- The distance between two successive similar fringes
(either bright or dark)
8-
Light is a wave motion.
9- The critical angle
:
is the angle of incidence in denser medium, its corresponding angle
of refraction in the less dense medium equal 90 o
10- a- When light is refracted to a medium n2
:
11-
Total internal reflection takes place when : -
The angle of
incidence in denser medium is greater than the critical value.
12-
Mirage is a phenomenon related to total internal reflection.
13-
The angle of the apex of the prism (A) is given by: A = 1
+ 2:
14- The angle of deviation "
"
is given by:
16-
In a thin prism :
17-
The angular dispersion for a thin prism is
18-
The " dispersive power "
Chapter Four : Hydrostatics
I)
Definitions and Basic concepts and Formuals:
1- The density (
)
:-
- is the mass of unit volume.
- is given by:
-
Is measured in kg / m3
2- Relative density : R.D
3-
The pressure at a point: P
- Is the average force acting
normally on a unit surface area surrounding this point:
- Is
given by:
-
Is measured in: N / m 2
4- The pressure at a point inside liquid of density
at depth h below its free surface:
-
All points inside the same liquid and lie at the same horizontal
plane have the same pressure.
5- The atmospheric pressure:
-
is a phenomenon related to the weight of the atmosphere of earth.
-
Is measured by "Barometers".
- The normal atmospheric
pressure: "atm" is equivalent to the pressure produced by
the weight of a column of Hg of 0.76 m height and base area 1 m2
at 0 o
C units of atomspheric pressure are:
a- Pascal (1N/m2)
b- Bar (105
N/m2)
c- Cm Hg
d- Torr (mm Hg)
6- When two liquid are
balanced in U-shaped tube:
7-
The manometer is an instrument for measuring the difference in the
pressure of a gas inside a container and the outer atmospheric
pressure.
- The pressure of gas is given by:
8-
Pascal's principle:
"The pressure applied to an enclosed
liquid is transmitted undiminished to every portion of liquid and to
walls of container."
9- The hydraulic press:
- It is
used to left heavy weights using small forces
-
In order to measure the distance moved by the small piston y1
use the relation: Fy1
= Fy2
10- Archimedes principle:
- "A body immersed wholly
or partially in a fluid experiences an upthrust force (buoyant force)
in the vertical direction equal to the weight of displaced fluid by
the body.
- It is given by:
"L"
density of fluid
"Vol
": volume of displaced fluid.
- Law of floatation:-
