This document discusses fluid mechanics concepts including: 1) Pressure in fluids acts normal to a submerged object's surface. 2) Fluid pressure increases with depth according to hydrostatic pressure relationships. 3) For a liquid in equilibrium, pressure is the same at all points in a horizontal plane to prevent net forces and fluid flow.

1. CH 11-FLUID
MECHANICS
Lect-01

2. Today’s Goal
1) Pressure in Fluids

3. 1. Liquids and gases can flow and are therefore, called
fluids.
Introduction
2. An Ideal Fluid is one which is
a) Incompressible
b) Non - Viscous

4. Pressure
Pressure is a scalar quantity
SI unit of pressure

5. units of pressure
units of Volume

7. •Pressure in Fluids
When an object is submerged
in a fluid at rest, the fluid
exerts a force on its surface.
This force is always normal to
the object’s surface

8. •Density of Fluids

9. •The relative density of a substance is the ratio of its
density to the density of water at 4oC.
•Relative Density /specific gravity

13. •Variation of Fluid Pressure with depth

16. •Graph between P and h

17. •Gauge Pressure and Absolute Pressure

20. a) 5km
b) 8km
c) 11km
d) 13km
Q)The density of the atmosphere at sea level is 1.29 kg/m3 .
Assume that it does not change with altitude. Then how high
would the atmosphere extend?

30. PA – PB = ?

31. •Variation of Fluid Pressure along the same
Horizontal Level
For a liquid in equilibrium the pressure
is same at all points in a horizontal
plane. Suppose the pressure were not
equal in different parts of the fluid,
then there would be a flow as the fluid
will have some net force acting on it.
Hence in the absence of flow the
pressure in the fluid must be same
everywhere in a horizontal plane.

32. •U – tube problems

36. Find x , so
that fluid
remains in
equilibrium
a) 1 cm
b) 2cm
c) 3cm
d) 4cm