1. 1
Unit 1 : Fluid And Properties
1. Define Fluid
2. Compare the characteristics between liquid, gas and solid
a. Liquid
b. Gas
c. Solid
3. Define of pressure
a. Atmospheric
b. Gauge
c. Absolute
d. Vacuum
-
The pressure below the atmospheric pressure ( vacuum)

2. 2
4. Example problem of pressure
a. What is the pressure gauge of air in the cylinder if the atmospheric gauge is
101.3 kN/m2 and absolute pressure is 460 kN/m2.(358.7kN/m2)
b. A Bourdon pressure gauge attached to a boiler located at sea level shows a
reading pressure of 7 bar. If atmospheric pressure is 1.013 bar, what is the
absolute pressure in that boiler (in kN/m2) ?(801 kN/m2)
5. Fluid properties
a. Mass density, ρ is defined as the mass per unit volume.
b. Specific weight,  is defined as the weight per unit volume.
c. Specific gravity or relative density, s is the ratio of the weight of the substance to
the weight of an equal volume of water at 4 ºC.
d. Specific volume, v is defined as the reciprocal of mass density. It is used to mean
volume per unit mass.
e. Viscosity
A fluid at rest cannot resist shearing forces but once it is in motion, shearing
forces are set up between layers of fluid moving at different velocities. The
viscosity of the fluid determines the ability of the fluid in resisting these shearing
stresses.
Kinematic viscosity
This ratio is characterized by the kinematic viscosity (Greek letter nu, ν),
defined as follows:
Dynamic viscosity, μ
6. Example problems of fluid properties

3. 3
a.
If 5.6 m3 of oil and weights 46000 N ,determine :
i. Mass density ,ρ in unit kg/m3
ii. Specific weight ,ω
iii. Specific gravity of oil , S
(837.33kg/m3,8214.3N/m3,0.837)
b.
Get the relative density , density , specific weight and kinematik viscosity
of an oil which are 7.3 m3 in volume , 6500 kg in mass and dynamic
viscosity is10-3Ns/m2
(s=0.89, ρ=890.41kg/m3,ω=8734.92N/m3 ,1.123x10-6m2/s)
c.
Determine the specific volume if it mass is 500g and the volume is 400cm3
(8x10-4m3/kg)
d. Given specific weight of fluid is 6.54 N/litter and its mass is 830 g . Calculate
the following in SI unit
i.Volume of fluid
ii.Specific volume of fluid
iii.Density of fluid (1.245x10-3 m3,1.5x10-3/kg,666.67 kg/m3)

4. 4
e.Volume and mass for oil are 9.2 m3 and 7300 kg
i.
ii.
iii.
Mass density
Relative density
Specific weight
(793.4 kg/m3 , 0.793,7.78x103N/m3)
f. If the mass and volume of air 11.5 kg and 650 cm3, calculate:
i.
Mass density
ii.
Specific weight
iii.
Specific volume
iv.
Specific gravity for the air
(17692.31 kg/m3,173558.5N/m3 , 5.352x10-5m3/kg)
g. The volume of engine oil is 5.5m3 and the weight is 50 kN determine
i.
Density of oil
ii.
Specific weight of oil
iii.
Specific volume of oil
iv.
Specific gravity
(926.7kg/m3,9091N/m3,1.079x10 -3 m3/kg, 0.9267)
h. Determine the mass density , in SI unit if it s mass is 450g and the volume is 9dm 3.
(50kg/m3)
i.
Determine the specific weight ω ( kN/m2) and specific gravity, s of fluid if the weight
is 100N and the volume is 500cm3
( 20kN/m3, 2.039)
j.
The volume of a stone is 1.5 x 10-4 m3. If the relative density of the stone is 2.6,
calculate:
i. The density
ii. The specific weight
iii. The specific volume
iv. The weight
v. The mass
3
( 2600kg/m , 25.506kg kN/m3,3.85 x10-4m3/kg, 3.83 N, 0.39 kg)

5. 5
k. Given the volume of oil is 3 liter and the weight is 20N, determine the specific
volume, relative density and specific weight of oil.
( 1.471 x10-3m3, 0.68,6670N/m3)
l. Specific gravity of a liquid is 0.85. determine
i. Mass density
ii. Specific volume
(850kg/m3,1.176 x 10-3m3/kg)