Slide 1
PENYUSUN :RAHMAWATI(4001410002)WAHYU ESTIANI (4001410006)IKA
RAHMAWATI(4001410042) DHARIS DWI A.(4001410045)MIKA SETYA
A.(4001410054)
KELOMPOK I
PENDIDIKAN IPA
FLUIDS
PENYUSUN :RAHMAWATI(4001410002)WAHYU ESTIANI (4001410006)IKA
RAHMAWATI(4001410042) DHARIS DWI A.(4001410045)MIKA SETYA
A.(4001410054)
2
There are three states of matter, i.e.:
solid,
liquid,
gas,
plasma
Solids is defined into
crystalline, ex.salt
amorphous, ex.glass
A liquid is incompressible and has definite volume but no
definite shape
A gas is easily compressed
Liquid and gases have an ability to flow. That is why both
liquid and gases are usually called fluid or the flowing
substance..
A plasma is an ionized gas and is yhe most common form of matter
in the universe, since the insides of stars are plasmas
Phases Charge
Solid
liquid
gas
2
3
4
5
6
1
Melting
Evaporate
Sublimate
Frozen
Sublimate
kondentate
The Term fluid refers to gases and liquids
1. Density
Density () of a material is defined as its mass (m) per unit
volume (V).
Mathemathically, density is formulated as:
=
Fluids will be divided into two parts, i.e. hydrostatics which
discusses about the static fluid or fluid at rest and hydrodynamics
which discusses about fluids in motion.
2. Pressure
Pressure is defined as the force per unit of area
P=
Atmospheric pressure= 105 P
Define of Hydrostatics
Fluid statics(also calledhydrostatics) is thescienceoffluidsat
rest, and is a sub-field withinfluid mechanics.
Liquid pressure in motionless is called hydrostatics
pressure.
Hydrostatics pressure depends on density, height or dept of
liquid, also earth gravitasional acceleration, so it can be
formulated as follows:
in which:
p= hydrostatics pressure (N/m2 or Pa).
= density of liquids (kg/m3)
g= Earth gravitasional acceleration (m/s2)
h= height or depth of liquid (m)
P=.g.h
Capillarity
Capillarity is the elevation or depression of liquid (fluid) in
a capillary tube. Some common example of capillary: the rise of
kerosene through a stove fuse; in rainy season, the wall gets wet
because it absorbs water.
Adhessive and Cohessive force cause the meniscus property of the
fluid surface so the vertical components of the upward force is
influenced by the contact-angle . The height of the fluid column in
the capillary tube:
h=
Pascals Law
Pascal is taken from the name of a French mathematician and
physicist. His full name is Blaise Pascal, he lived from year 1623-
1662.
pascal expressed that:
Pressure given to liquid in closed chamber will be continued by
the liquid to every direction with uniform and the same
magnitude.
One of the applications of Pascals Law is hydraulic lift.
ArchimedesLaw
Archimedes law states that when a body is immersed in a fluid ,
the fluid exerts an upwards force (buoyant force) on the body whose
magnitude is equal to the weight of the fluid displaced by the
body.
Mathematically formulated as :
FA= fluid V g
There are three possible cases of a body in a fluid, i.e.
floating, barely floating (completelly submerged), and sinking.
Floating
A body is said to be floating if only some parts of the body is
submerged or beneath the water surface. On a floating body, the
magnitude of buoyant force FA is equal to the bodys weight w=
mg.
FA=mg
fluida gVt= bVbg
fluidaVt= bVbg
Suspending
A body is said suspending if the body is immersed at all but des
not reach base of the liquid.
w=Fa
b.Vb.g = a.Va.g
Vb=Va
b=a
Sinking
A body is said sinking if the body is immersed at all and lies
on the base of a liquid.
w>Fa mb.g>ma.g
(Vb.b).g>(Va.a).g
Aplications of Archimedes Law
1. Ponton bridge
2. Ship
3. Hydrometer
4. Submarine
5. dock
Viscosity
Viscosity is the tendency to resist flow
On liquid, viscosity is caused mainly by the cohesive force
between its moleculs; meanwhile on gases, viscosity is caused by
collicions between its molecules.
We can observe viscosity by droping a marble into a glass of
cooking oil. The magnitude of the frictional force on the marble
moving at its conctant velovity:
f=6rv
Surface tension
Surface tension is defined as the force along a line per unit
length which is parallel to the surface. The magnitude of surface
tension () of an object having one surface :
=
For an object with to surface, the equation become : =
Thus, we can say that each molecule can only be atracted by its
neighboring molecule.
Aplication of surface tension in everyday life:
Using soap or detergent which has an effect to decrease the
surface tension.
Small insect walk on its surface floating.
Hydrodynamics
Hydrodynamics is a brancah of physics that studies about the
motion of fluid.
Hydrodynamics will be divided into two parts, i.e. true fluid
and ideal fluid.
Ideal fluid is fluid with properties of: incompressible(the
density of the fluid does not depend on the pressure, it can not be
compressed). The ideal fluid flow is linear (streamline), it mean
that the flow is not turbulent.
The Continuity Equation
Volume flow rate (Q) is defined as the amount ( volume) of fluid
flow per time unit.
Mathematically, the rate of volume flow is formulated as:
Q =
Q = A.v
Q1=Q2 or A1.v1=A2.v2
2. Bernoullis Equation
The complete form of Bernoullis equation:
P1+ V12 +gh1 = P2+ V22 +gh2
Applicaton of Bernoulis Principle
Flow from a tank hole.
v2=
Calculate hydrostatic pressrue of water at the point t (see
figure besides), with depth of h = 30 cm from water surface, if
given density of water = 1000kg/m3 and earth gravitational
accaleration = 10 m/s2.!
Solution:
Given: h=30 cm = 0,3 m
=1000kg/m3
g=10 m/s2
Asked: p=.?
Answer: p=gh
=1000kg/m3 . 10 m/s2 . 0,3 m
= 3000kg/ms2
= 3000 N/m2
What would be depression of mercury inside a coulumn with a
radius of 2 mm, given that the contact angle between mercury and
glass is 1500 , surface tension is 0.545 N/m , gravitational
acceleration (g) is 10 m/s2, and the density of mercury is 13.600
kg/m3?
Solution:
Given: r= 2mm=0.002m; = 1500 ; =0.545N/m; g= 10 m/s2 ; = 13.600
kg/m3
Asked: h..?
Answer: h=
=
=- 3.48x10-3 m
= - 3.48 mm
Thanks for your attention
