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 PascalPrinciple
■ Introduction
Did you know that most aircraft use
incompressible fluid in the braking system
and landing gear?

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

5. Applying PascalPrinciple
■ 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 PascalPrinciple
■ As the pressure transmitted through
the fluid is the same, and as pressure,
, therefore :
Where;
F1 = the small force applied
A1 = the small area
F2 = the large force applied
A2 = the large area
2
1
2
1
A
A
F
F

A
F
P 
The small force (F1) exerts a
larger force (F2)

7. Applicationof PascalPrinciple
Hydraulic
System

8. Applicationof PascalPrinciple
Hydraulic Lift

9. Applicationof PascalPrinciple
Lever Piston A Piston B Effect
Step-down
(small piston
is pushed
down)
Open Close The hydraulic oil flowing
into the master cylinder.
The is being raised.
Step-up
(small piston
is pulled up)
Close Open Hydraulic oil is drawn
from the reservoir into
the space under the
small piston. The car at
original position.

10. Applicationof PascalPrinciple
■ Hydraulic lifts are used to elevate the heavy items such as
car or trucks.
out
out
in
in
P
F
P
F

Pin is equal to the output pressure, Pout ,
Pin = Pout
in
in
out
out F
A
A
F 
Since Aout is much bigger than Ain, the resulting force multiplier
effect enables a heavy object like a car to be lifted by a much
smaller input force.