Flashcards: Mechanical Properties of Fluids

 Page 1


Mechanical Properties of Fluids
Flash cards
Page 2


Mechanical Properties of Fluids
Flash cards
Pressure in a fluid (continued)
where dF
?
is the small compressive force perpendicular to the surface area dA
including the point.
Page 3


Mechanical Properties of Fluids
Flash cards
Pressure in a fluid (continued)
where dF
?
is the small compressive force perpendicular to the surface area dA
including the point.
Pressure in a fluid (continued)
Note 1
For equilibrium of solids we usually think in terms of forces while for liquids we 
usually think of pressure. Since in solids the actual area of contact is much smaller 
than the apparent area of contact between two surfaces, so the concept of pressure is 
of no use. But in case of liquids the actual area of contact is same as the apparent 
area of contact.
Page 4


Mechanical Properties of Fluids
Flash cards
Pressure in a fluid (continued)
where dF
?
is the small compressive force perpendicular to the surface area dA
including the point.
Pressure in a fluid (continued)
Note 1
For equilibrium of solids we usually think in terms of forces while for liquids we 
usually think of pressure. Since in solids the actual area of contact is much smaller 
than the apparent area of contact between two surfaces, so the concept of pressure is 
of no use. But in case of liquids the actual area of contact is same as the apparent 
area of contact.
Pressure in a fluid
Note 2
Pressure acts normal to a surface and it is always compressive in nature, i.e., only its 
magnitude is required for its complete description. It is a scalar quantity.
Note 3
The SI unit of pressure is N/m
2
or pascal (Pa). The other common units are, 1 atm = 
1.013 × 10
5
Pa and 1 bar = 10
5
Pa
Page 5


Mechanical Properties of Fluids
Flash cards
Pressure in a fluid (continued)
where dF
?
is the small compressive force perpendicular to the surface area dA
including the point.
Pressure in a fluid (continued)
Note 1
For equilibrium of solids we usually think in terms of forces while for liquids we 
usually think of pressure. Since in solids the actual area of contact is much smaller 
than the apparent area of contact between two surfaces, so the concept of pressure is 
of no use. But in case of liquids the actual area of contact is same as the apparent 
area of contact.
Pressure in a fluid
Note 2
Pressure acts normal to a surface and it is always compressive in nature, i.e., only its 
magnitude is required for its complete description. It is a scalar quantity.
Note 3
The SI unit of pressure is N/m
2
or pascal (Pa). The other common units are, 1 atm = 
1.013 × 10
5
Pa and 1 bar = 10
5
Pa
Variation of pressure
Variation of pressure in fluids can take place in several ways due to several reasons. 
We can classify them as follows: