Pascal's principle

State Pascal’s principle
Explain hydraulic system,
Describe the applications of Pascal’s principle,
Solve problems involving Pascal’s principle.

1. CHAPTER 3
3.4 Pascal’s Principle
FORCES AND
PRESSURE

2. 3.4 Applying Pascal’s Principle
■State Pascal’s principle
■Explain hydraulic system,
■Describe the applications of Pascal’s principle,
■Solve problems involving Pascal’s principle.

3. Applying Pascal Principle
■Introduction
Did you know that most aircraft use
incompressible fluid in the braking system
and landing gear?

4. Applying Pascal Principle
■Pascal’s Principle states that pressure applied to an
enclosed liquid is transmitted equally to every part
of the liquid.

5. Applying Pascal Principle
■An apparatus consist that of a glass barrel
fitted to a plunger and ending with a bulb with
holes of uniform size.
■This apparatus is fully filled with water.
■When the plunger is pushed in, the water spurts
equally from all the direction.

6. Applying Pascal Principle
■As the pressure transmitted through
the fluid is the same, and as pressure,
, therefore :
Where;
F
1= the small force applied
A
1= the small area
F
2= the large force applied
A
2 = the large area2
1
2
1
A
A
F
F
 A
F
P
The small force (F
1) exerts a
larger force (F
2)

7. Application of Pascal Principle
Hydraulic
System

8. Application of Pascal Principle
Hydraulic Lift

9. Application of Pascal Principle
Lever Piston APiston B Effect
Step-down
(small piston
is pushed
down)
Open CloseThe hydraulic oil flowing
into the master cylinder.
The is being raised.
Step-up
(small piston
is pulled up)
Close OpenHydraulic oil is drawn
from the reservoir into
the space under the
small piston. The car at
original position.

10. Application of Pascal Principle
■Hydraulic lifts are used to elevate the heavy items such as
car or trucks.out
out
in
in
P
F
P
F

P
in is equal to the output pressure, P
out,
P
in = P
outin
in
out
out
F
A
A
F 
Since A
outis much bigger than A
in, the resulting force multiplier
effect enables a heavy object like a car to be lifted by a much
smaller input force.